Time Zone Abbreviations

If you’re familiar with time zones, it’s useful to know some of the most commonly used time zone abbreviations. Knowing time zone abbreviations makes it easier to navigate time differences around the world: if you know what UTC, GMT, CET, or EST means, you can easily figure out what time it is in Europe, North America, or anywhere else around the world. It’s not necessary to know all the time zone abbreviations by heart (although, technically, this would save you time – pun intended), but it helps to quickly figure out which abbreviation stands for which time zone, especially if you’re scheduling social or business calls across different countries.

So let’s start at the beginning and first look at UTC and GMT abbreviations.

UTC and GMT

GMT stands for the Greenwich Mean Time, whereas UTC stands for the Coordinated Universal Time. What’s the difference? GMT is a time zone, whereas UTC is a time standard used for regulating the world’s clocks. GMT represents the Prime Meridian, or the zero longitude, whereas UTC represents the standard 0 hour time according to which all time zones are regulated. Anything West of GMT will have a negative time offset, whereas anything East of GMT will have a positive UTC offset. 

Countries and cities in the GMT time zone include: United Kingdom, Portugal, Canary Islands (Spain), Faroe Islands, Burkina Faso, Gambia, Ghana, Guinea, Guinea-Bissau, Iceland, Ivory Coast, Liberia, Mali, Mauritania, Saint Helena, Ascension and Tristan da Cunha, Senegal, Sierra Leone, and Togo.

DST: Daylight Savings Time

Besides GMT and UTC, another important abbreviation to remember is DST which stands for the Daylight Saving Time. Daylight Saving Time is used to extend daylight hours seasonally: some countries around the world use DST moving their clocks forward in summer and backward in winter to enjoy more daylight; however, not all countries use this practice, and not all people are happy with it. DST was first introduced during World War I as a means to save energy, and in most countries around the world, the concept stuck. However, this adds confusion to time zone differences: for example, Australian Eastern Time (AEST) is UTC +10, but between March and November, the locals move their clocks forward, and it becomes the Australian Eastern Daylight Time which is in UTC +11:00. This si done in many countries, states, and territories around the world, so when you’re trying to figure out time differences across the globe, make sure you take DST into account – sometimes, it may mean a difference of an hour you might forget to account for.

Now that you’ve got your GMT, UTC, and DST abbreviations figured out, let’s take a look at time zone abbreviations used around the world. Each time zone abbreviation corresponds to a specific time zone around the world, but it is not always defined by geography only – some countries and territories around the world choose to observe just one time zone, a time zone observed by its neighbours, or create their very own time zone or time offset.

Here is a comprehensive list of time zone abbreviations around the globe:

ACST: Australia Central Standard Time

Australia has several different time zones, and Australia Central Standard Time (ACST) stands for UTC+09:30, used in the central part of the country. Major cities in the Australia Central Standard Time include Darwin, Adelaide, and Alice Springs.

AEST: Australia Eastern Standard Time

Australia Eastern Standard Time is just half an hour ahead of ACST, falling on the UTC+10:00. AEST is observed in Eastern Australia with major cities like Melbourne, Sydney, and Brisbane in its sphere. Note that Eastern Australia switches to daylight savings time during the summer months, moving the clocks forward one hour and using the UTC+11:00 time zone.

AWST: Australia Western Standard Time

In Western Australia, locals observe the AWST, or the Australia Western Standard Time which is UTC +09:00. One of the biggest cities in AWST is Perth.

AFT: Afghanistan Time

Afghanistan is among the few countries that prefer an offset of half an hour rather than a full hour, making timekeeping in Kabul interesting. Afghanistan uses UTC+4.30, making the AFT a rather curious time zone.

AKST: Alaska Standard Time

Alaska Standard Time is an interesting one, too: despite the fact that Alaska’s territory spans over five time zones, the state uses just one – the AKST, or the Alaska Standard Time – for convenience. AKST is UTC-9:00, but during the summer months, it’s switched to Alaska Daylight Time.

AST: Atlantic Standard Time

AST, or the Atlantic Standard Time, is a good one to remember as it covers several countries like Antigua and Barbuda, Barbados, and the US Virgin Islands. Atlantic Standard Time is UTC-04:00, and from March to November, it changes to Atlantic Daylight Time one hour ahead.

CAT: Central Africa Time

What’s common between Botswana, Malawi, Namibia, Rwanda, and Sudan? The time zone! These countries observe CAT, or Central African Time, which is UTC +02:00. Essentially, CAT time is the same as GMT +2 time zone.

CET: Central European Time

Central European Time, or CET, is a time zone that covers a long list of European countries like Albania, Andorra, Austria, Belgium, Bosnia and Herzegovina, Croatia, Czech Republic, Denmark, France, Germany, Hungary, Italy, Kosovo, Liechtenstein, Luxembourg, Malta, Monaco, Montenegro, Netherlands, North Macedonia, Norway, Poland, San Marino, Serbia, Slovakia, Slovenia, Spain (except Canary Islands), Sweden, Switzerland, and Vatican City. CET is UTC+01:00, and major cities in this time zone include Amsterdam, Berlin, Warsaw, Brussels, Madrid, and Rome. Most countries in CET switch to daylight savings time during the summer months.

CST: Central Standard Time

CST, or Central Standard Time, covers the central part of the US and Canada. CST is UTC+06:00, and it covers Alabama, Arkansas, Illinois, Iowa, Louisiana, Minnesota, Mississippi, Missouri, Oklahoma, and Wisconsin in the US as well as Manitoba in Canada and several states in Mexico.

EAT: East Africa Time

EAT, or East Africa Time, is in UTC + 03:00, and it covers Kenya, Somalia, Madagascar, Ethiopia, Eritrea, Djibouti, Tanzania, and Uganda.

EET: Eastern European Time

EET stands for Easter European Time which is UTC +02:00, covering Bulgaria, Cyprus, Estonia, Finland, Greece, Latvia, Lithuania, Moldova, Romania, and Ukraine. Most of these countries observe daylight savings time.

EST: Eastern Standard Time

Eastern Standard Time, or EST, time zone covers large swaths of North, Central, and South America, and is UTC -05:00. Countries that use EST include United States, Canada, Mexico, Bahamas, Tahiti, Panama, Brazil, Colombia, Peru, and Ecuador.

MSK: Moscow Standard Time

Can a city have its very own time zone? Yes, if that city is Moscow: MSK stands for Moscow Standard Time, which is in UTC +03:00. MSK isn’t just used in Moscow, however: Belarus, parts of Ukraine, and parts of Russia also adhere to the Moscow Standard Time.

MST: Mountain Standard Time

MST, or Mountain Standard Time, is in UTC -07:00 and covers US states of Colorado, Montana, Wyoming, New Mexico, Arizona, and Utah. In Canada, the province of Alberta and part of British Columbia use MST, too, and in Mexico, Baja California, Chihuahua, Sonora, and Sinaloa fall under the Mountain Standard Time.

PST: Pacific Standard Time

If you work or communicate with people from LA or Las Vegas, PST, which stands for Pacific Standard Time, is an important abbreviation to remember. PST is UTC-08:00, and it covers the states of California, Washington, Idaho, Nevada, and Oregon in the US as well as British Columbia in Canada and part of Baja California in Mexico.

WAT: West Africa Time

WAT stands for West Africa Time which is UTC +01:00. WAT covers countries like Angola, Benin, Cameroon, Central African Republic, Chad, Congo, The Democratic Republic of Congo, Guinea, Gabon, Niger, and Nigeria.

WET: Western European Time

WET, or Western European Time, is the same time zone as GMT as it is in UTC 00:00. Countries in the Western European Time include the United Kingdom, Ireland, Iceland, and Portugal.

Once again, when calculating time differences between time zones, don’t forget to factor in the DST both in your own country and the one you’re determining the local time in. Whether the actual time zone offset is an hour, half an hour, or even just fifteen minutes (looking at you, Nepal!), if you don’t add the DST differences in, you may be way off when scheduling calls or meetings. And easy way to figure out whether a time zone abbreviation already has the DST factored in is to look for that “D”: for example, the Australian Eastern Time (AET) becomes the Australian Eastern Daylight Time (AEDT) during the summer, the “D” betraying the daylight savings. This is common across most time zone abbreviations regardless of geographical location.

Now that you know all the most commonly used time zone abbreviations, you’ll never mess up your work or social schedule whenever it involves international calls or meetings!

AKST – Alaska Standard Time

Alaska Standard Time is nine hours behind the Coordinated Universal Time (UTC-9); during the daylight saving time, the offset is eight hours from UTC. However, the entire territory of Alaska easily spans over five time zones – as many as the contiguous United States – and a large portion of the state actually falls under the UTC-10 an UTC-11 time zone rather than the Alaska Standard Time. In fact, Cape Wrangell should technically fall into UTC-13 as the sun sets at midnight here, and Adak time is more towards UTC-12 – not the UTC-9 of the Alaska Standard Time. To add to the confusion, the Alaska Standard Time is the same as Hawaiian time…

Wait, what?

How does that work, and what is UTC in the first place?

Let’s take a look: if you work or communicate with people living in Alaska, it pays to understand the time zones and time zone differences, so you always time your calls or work schedules right. After all, no one wants to be woken up at 3am to answer a business call or log in to a Zoom meeting at midnight. 

In the following sections, we’ll explain what Coordinated Universal Time is, how to calculate time zone differences, and how Alaska Standard Time or AKST is observed throughout the year. At the end of the article, we’ll share some fun facts about time zones – we bet you’ll be blown away how some parts of the world observe their time!

Timing it Right: Coordinated Universal Time

Time zones were first introduced in the nineteenth century, when the need to have coordinated time around the globe for trade, military, and transportation purposes became all too important. The proposal was simple: since the Earth rotates 15 degrees every hour, that means that midday occurs at different times around the world. Taking the Greenwich Meridian as longitude zero, if you travel West by 15 degrees, the midday will occur one hour earlier than on Greenwich, and if you travel fifteen degrees East, it will be an hour late. The Earth has 24 slices of 15 degrees each, and that’s your time zones right there.

However, Greenwich Mean Time (GMT), it turns out, isn’t as accurate as we previously thought. Sometimes, there are slight discrepancies in the earth’s rotation, causing what is known “leap seconds” – they occur when the Earth’s rotation is a little slower or faster than usual. It’s just seconds, but for the sake of accuracy, in 1972, it was agreed to observe Coordinated Universal Time which is monitored by highly precise atomic clocks so that the “zero hour” always remains the same and isn’t slowly drifting away.

Ever since, UTC has become a time standard, whereas GMT remains a time zone – but no longer a time standard.

Now, the time zone differences are calculated using UTC. Anything West of UTC will have a negative offset by one, two, three or more hours, depending on the longitude; equally, anything East will have a positive offset depending on location. Don’t let geography confuse you, though: time zones are “sliced” vertically rather than horizontally, which means that countries thousands of miles from each other may be in the same time zone, and countries relatively close to each other observe different time. Cape Town and Madrid are in the same time zone, but Madrid and Lisbon are not: this is because time zones are calculated by West-East reference rather than North-South.

Alaska Standard Time

If time zones are 15 degrees of longitude each, how is it possible that Alaska spans over five time zones, but only observes two?

The answer is simple: convenience. During the winter months, Alaska observes the Alaska standard Time or abbreviated AKST (UTC-9), and from March to November, the locals wind their clocks forward to observe the daylight savings time. This wasn’t always the case – in the early twentieth century, Alaska had a tough time figuring out its own timekeeping as several time zones (UTC-10, -9, and -11 were observed throughout the state, and Alaska varied between Yukon Standard and Pacific Standard Time, while Nome and the Aleutians observed Bering Standard Time). In 1918, the Interstate Commerce Commission was tasked with defining a unified Alaskan time for trade and commerce purposes, and the majority of Alaska observes the Alaska Standard Time since.

This, however, isn’t without its own challenges and peculiarities. Alaska spans several time zones, which means that the westernmost parts of the state are off by almost three hours from Central Alaska, and the easternmost parts are off by even more hours than the West. During the daylight savings time in the summer, this is even more pronounced: for example, the sun sets at about 9.40 pm in Anchorage, but the time there is actually 11.40 – in other words, a midnight sunset. In Juneau, on the other hand, it’s the other way round. In Fairbanks, sunset can occur as late as 12:40 the next day; in Nome, the sunrise occurs at 12:02 p.m., about 4 hours before sunset at 3:56 p.m. Crazy, right?

Not necessarily: as large portions of Alaska are more or less uninhabited, the locals hardly notice – and having one time zone makes it easier to coordinate time. On the other hand, Alaskans sometimes take it upon themselves to figure out what time works best: for example, the town of Hyder in the Inside Passage unofficially observes two time zones. Hyder is divided by the US-Canadian border and the locals here observe Pacific Time – except for the postal works. The US Post Office in Hyder, as a federal US facility, is on Alaska Time regardless of what the locals prefer.

The relaxed attitude Alaska has on timekeeping is down to the state’s history. Essentially, in the US and Canada, time zone unification and keeping exact time became necessary in the 1850s when the expanding network of railroads demanded each town to keep an exact time to avoid collisions at crossing points; in order to have the trains operating safely, time needed to be precise. By 1880s, the railroads established Eastern, Central, Mountain, and Pacific time zones. Alaska, however, had no railroads – and here, exact time mattered little until around 1903, when the US military began constructing a telegraph system connecting the towns in Alaska, which required a more accurate timekeeping.

Territories and Cities in Alaska Standard Time:

Cities:

  • Anchorage
  • Fairbanks
  • Juneau

Territories:

  • The state of Alaska

Interesting Time Zone Facts

  • Accurate timekeeping and time zone differences are an obvious necessity in these days, but it wasn’t always the case: just two centuries ago, people were happily oblivious to exact time. Farmers rose and went to bed when the sun rose or set, and most people went about their day without worrying about hours and minutes: for example, in 1790, fewer than ten percent of Americans had clocks, and most of the clocks they did have had no minute hand.
  • Two places on Earth still have no official time to this day: The South and the north Poles. This is because the longitude lines that define time zones meet at the Poles, making them…well, timeless. Scientists who work on the Poles usually keep their own country’s time or simply stick to GMT.
  • Speaking of timeless: the International Space Station is constantly orbiting the Earth, adhering to no time zone at all. To keep things simple, the ISS follows GMT, much like the South or the North Pole.
  • Alaska’s decision to observe just one time zone when the territory covers five may seem odd, but not to the Chinese. Although China spans several time zones just like Alaska, there is only one time observed across the country: Bejing time. This means that sunrise isn’t until 10 am in Eastern China, but somehow, the locals manage. India is another country that has only one time zone despite being so vast it could easily observe several.
  • After all, time is just an agreement: although France is on the same meridian as the UK, Paris observes a GMT+1 timezone. Because they’re French – but also because this helps to facilitate trade and commerce with other European countries much easier. Sorry, England.
  • Some countries take it a step further and have half-hour or even fifteen-minute offsets: Nepal Myanmar, India, and Afghanistan among others observe thirty or fifteen-minute time offsets. Talk about timing it right…
  • …or time travel: UTC -12 and UTC+12 are the same time zone, just with a different date. If you were to travel from Gilbert Islands, which are in the UTC+12 time zone, and arrived in Baker Island on the Pacific Ocean, your time would be the same – but your date would be a day off. 
  • Shockingly, a few places on Earth use time zones that do not exist – UTC+ 13, +14, and +15. Pacific Ocean islands of Tonga, Tokelau, and Samoa use the UTC+13 time zone, and Kiritimati uses UTC+14. Does that mean they have 15-hour days? Not quite – this is because they’re located right atop the date line, making it all the more confusing. 

AST – Atlantic Standard Time

Understanding time zones and time zone differences is key in this day and age where we often work, socialize, and connect with people around the globe. At a first glance, time zones may appear confusing, especially when you throw daylight savings time into the mix. However, there’s a simple hack to figure out time zones and different time around the world quickly, and it all starts with the concept of…sunrise. 

Intrigued? Be sure to keep reading to find out an easy way to calculate time differences around the globe quickly, learn about the Atlantic Standard Time – the AST time zone that covers over 25 countries worldwide – and find some fun facts at the end of the article to keep you entertained while you work out the global time.

Time Zones Explained

Here’s the thing: the Earth is a rotating sphere (sorry, flat earthers), and that means that the rising sun hits different parts of the globe at different times. In other words, when it’s dawn in LA, it’s already dusk in Paris – that’s because as the Earth rotates around the sun, different parts of it are exposed to daylight.

So if it’s dawn in LA and dusk in Paris, what’s the time in the US and what’s the time in France? It can’t be the same – and that’s where time zones come in. In 1878, a Scottish engineer, Sir Sanford Fleming, proposed a simple way to measure time around the globe: since the Earth rotates fifteen degrees every hour (that is, 360 degrees in 24 hours), it makes sense to divide the world into twenty-four time zones, each 15 degrees of longitude apart.

Now, the starting point of measuring time zones is the Greenwich Meridian, or longitude zero. Going West from here, you’ll need to subtract hours, and going East, add them: in other words, if it’s West of Greenwich, it will have a negative time difference (going “backwards”), and if it’s East, it’ll be “going forward”. For example, Madrid is GMT -2, whereas Moscow is GMT +3. Looking at time zones this way, you can easily calculate time differences by subtracting or adding hours depending on the geographical location.

There’s just one kicker: GMT is no longer a time standard. Wait, what? While GMT remains a time zone, since 1972, Coordinated Universal Time (UTC) became the world’s time standard. This is for the sake of accuracy – the GMT cannot be used as a time standard because of tiny, atomic discrepancies in the Earth’s rotation (it may take a few seconds slower or faster from year to year). To avoid these discrepancies, UTC is calculated by highly accurate atomic clocks, and for decades now, UTC has been used as the time standard around the globe. And so, when calculating time differences, you’ve got to look at the UTC rather than GMT offset.

So how does it all work in real life? Let’s take a closer look at one of the time zones – the Atlantic Standard Time – to figure it out.

What is Atlantic Standard Time

Atlantic standard Time, as the name suggests, covers the area along the Atlantic coast – namely, the easternmost parts of Canada, the US, the Caribbean, and parts of South America. Atlantic Standard Time is four hours behind UTC, that is, it’s UTC-4. The interesting thing is, while it covers large parts of the US and Canada, it’s only used in Newfoundland and Labrador and, when it comes to the US, Puerto Rico and the Virgin Islands.

To make matters even more confusing, the Atlantic Standard Time is only observed between the first Sunday in November and the second Sunday in March. During the summer and fall months, it cedes to the Atlantic Daylight Saving Time (ADT).

And to top it all off, several New England states in the US are considering shifting to the Atlantic Standard Time as the new norm. In 2017, there was a proposal that shifting to the Atlantic Standard Time (year-round, with no changes to daylight savings) would be highly beneficial; Florida, at the same time, is aiming for the “Sunshine Protection Act” where the state would observe the Eastern Daylight Time – equivalent to the Atlantic Standard Time – year round, to keep those sun-drenched hours as long as possible daily. These changes may take a while – they can only take effect when it’s passed into federal law by the US Congress – but the Atlantic Standard Time clearly has fans all the way from New York to Miami.

Countries in Atlantic Standard Time

Whether they observe the Atlantic Standard Time or not, and whether daylight savings time changes apply or not, the AST covers a large area. Countries covered by the Atlantic Standard Time include:

  • Antigua and Barbuda 
  • Barbados 
  • Brazil, in the following areas: Amazonas, Mato Grosso, Mato Grosso do Sul, Rondônia, Roraima 
  • Bolivia 
  • Canada, in the following areas: Nova Scotia, New Brunswick, Prince Edward Island, Most of Labrador, Magdalen Islands, Quebec,Côte-Nord 
  • Chile (except Magallanes region and Antarctic territory)
  • Dominica 
  • Dominican Republic 
  • France and French overseas territories, in the following areas: Guadeloupe, Martinique, Saint Barthélemy, Saint-Martin 
  • Greenland, in the following area: Thule Air Base, Grenada, Guyana 
  • Netherlands and Dutch special municipalities, in the following areas: Aruba, Bonaire, Curaçao, Saba, Sint Eustatius, Sint Maarten 
  • Paraguay
  • Saint Kitts and Nevis 
  • Saint Lucia 
  • Saint Vincent and the Grenadines 
  • Trinidad and Tobago 
  • United Kingdom (British Overseas Territories), in the following areas: Anguilla, Bermuda, British Virgin Islands, Montserrat (no DST)
  • United States, in the following areas: Puerto Rico, United States Virgin Islands 
  • Venezuela (no DST)

Interesting Time Zone Facts

If your head is already spinning trying to figure out time zones, places where the Atlantic Standard Time is observed, and differences in time around the world, it’s time to delve into the fun part of the AST time zone explanations: some fun facts about time zones worldwide! Here’s a list of our favourites:

  • Newfoundland kind of observes the Atlantic Standard Time… but it also kind of observes the UTC-3 time zone, resulting in the island having its very own offset – half an hour. This is because it sits right smack in the middle of both time zones, so, being practical, the Newfoundlanders found a way to appease both sides.
  • Speaking of quirky time zone decisions, China tops all charts: in 1949, China has standardized all of its time zones to Beijing time. Having in mind how vast the country is, it’s hard to imagine how it’s 7am in Beijing and 7am in Xinjiang at the same time despite a 2,000-mile distance, but who are we to argue – time, after all, is relative. China’s closest neighbours such as Pakistan may beg to differ, though – because of China’s one time zone policy, there’s a three-hour difference between China and Pakistan right across the border. As soon as you cross it, you’ll need to turn your clock backward of forward three hours, even if the crossing itself took a few minutes.
  • While China’s timekeeping decisions may sound a tad odd, France isn’t far behind: it’s the only country in the world where, officially, the sun never sets thanks to France’s remaining territories around the globe. Louis XIV would be pleased.
  • Much like Newfoundland, not all countries around the world follow the standard UTC offset of an hour. Ever-original, India uses an offset of five and a half hours, and Nepal has decided to observe UTC +05:45, so if you’re traveling to the Himalayas, get your minutes right!
  • Ever felt nostalgic about “Yesterday”, the famous hit song by John Lennon? Thanks to time zones, you can actually travel to…yesterday. You can depart from, say, Rome at 7am Monday morning and find yourself back on Sunday in San Francisco. We’re all for longer weekends, if you ask us.
  • Time travel can also be fun: if you feel like celebrating Christmas, New Year’s Eve, or your birthday multiple times a day, just book a ticket flying West, wind the clock back, and keep on partying!
  • On the other hand, hopping across time zones can be exhausting – jetlag is a price you pay traveling long distances, whether you’re heading West or East. Curiously enough, it’s Eastward travel that drains the energy the most as it extends the day forcing our bodies to stay awake and alert longer. Traveling West, your day s actually shortened, so your body can catch up on some rest. Pro tip? If jetlag is a constant struggle, power nap while in the air – short periods of zzz can help you adjust to a different time zone faster.

So thee you have it: whether you live in an area that observes the Atlantic Standard Time or perhaps often work or communicate with people who do, you now know how to calculate the time difference and stay on top of your scheduling game at all times (pun intended).

CET – Central European Time

People often dream about traveling in Europe. This small continent consists of plenty of beautiful countries that tend to attract tourists from various parts of the world. So, if you’re Getting to know Central European Time and other European time zones, it’s important to avoid confusion about the plane or train schedules and have better communication with the locals. 

However, people often feel confused about traveling through different time zones. Not only do they hate the puzzling sensation of jetlag, but also they hate being disoriented and lost. If you live somewhere around North America, chances are high that you understand the ways how Central Standard Time, Mountain Time, or Eastern Time work. But none of these time zones are familiar to European people. 

In fact, currently, European people measure the time based on the three standard time zones: Western European Time, Central European Time, and Eastern European Time. Among them, Central European Time or CET is observed in 17 EU member countries. It’s the most common time zone in the entire continent, covering the largest part of the EU population. 

In this article, we will discuss everything that you need to know about Central European Time. We will explain the way it works, review its brief history and teach you how to convert CET to different time zones. Since people often have questions about the similarities between CET and GMT, we will compare these two time zones. The complete list of the territories that cover CET will also be provided. 

CET Central European Time

What is CET Time?

Central European Time also known as CET is one of the time zones, mainly identified with European countries. However, CET isn’t used only in Europe. In fact, some African countries also observe Central European Time, alongside “local” time zones such as West Africa Standard Time or East Africa Time. CET covers a number of countries starting from western Spain up to the East. Totally, 35 countries are located in this time zone which is why the majority of people are aware of Central European Time. 

The most important thing about CET is to remember that it’s 1 hour ahead of Coordinated Universal Time (UTC). This time zone is usually used during the standard time in Europe and Africa. The time offset of CET from UTC is usually written as UTC+01:00. Even though Central European Time is the most common name of this time zone, in some parts of the world it’s known with different names. Specifically, people also call it Middle European Time (MET) or use colloquial names such as Madrid Time, Paris Time, Berlin Time, Warsaw Time, etc, in order to indicate CET time. 

CET is located on the 15th meridian east of Greenwich, the central axis for UTC+01:00. All EU countries that observe Central European Time also use Summer Time or Daylight Saving Time from the last Sunday in March to the last Sunday in October. Central European Daylight Time (CEDT) is 2 hours ahead of UTC (UTC + 2:00) and is the same as time zones such as Central Africa Time, Eastern European Time, or South African Standard Time. 

Brief History of CET

The history of time is one of the most puzzling, yet interesting topics. People often wonder how the world came up with the decision to divide the earth into various time zones. Centuries ago, the most accurate way to measure time was to use natural resources such as the sun, moon, and stars. Ancient people used to determine the position of the sun in order to make predictions about the entire day. A lot of years have passed since then and the time system has drastically improved. However, the current time system comes from the calculations of time based on the position of the sun.

Standard time was first introduced in the 19th century when people understood the need for time standardization. It was first used by British railways in 1847. The reason was that every railway station calculated time according to local time zones. As a result, it was almost impossible to provide an informative train schedule. Therefore, everything started from the railway industry but people around the world quickly realized the benefits of standardized time. By 1855, the majority of British clocks were already standardized to Greenwich Mean Time (GMT). 

Germany was the first country that started using Central European Time (CET) in 1893. By this time, the country was called the German Empire and the introduction of CET meant unifying of time zones. CET was called MEZ in Germany which is a German abbreviation of Middle European Time. The empire implemented the new time system in all occupied territories during World War I. 

Lithuania started using CET or MET in 1920 and observed CET until 1940. Other countries that observed European Standard Time before World War II were France, Belgium, Netherlands, and Luxembourg. After the war, other European countries (Monaco, Spain, Andorra, and Gibraltar) also implemented CET in their national time system. Portugal also used CET in 1966-76 and 1992-96 but today the country observes Western European Time. 

How Does CET Work?

The basic mechanism of Central European Time (CET) is exactly the same as other time zones. It’s one of the 24 15-degree parts of the earth that covers 35 countries in Europe and North Africa. The clocks of the countries in the CET time zone are set accordingly. 

People usually determine the time in relation to UTC, a primary time standard according to which the clocks and time are regulated around the world. one of the time zones that are 1 hour ahead of Coordinated Universal Time (UTC). Therefore, the time offset of the CET is UTC+1 which is the same as GMT+1. 

However, CET is not the only time observed by the countries in this time zone. Many countries also observe CEDT which is an abbreviation of Central European Daylight Time. Using Daylight Saving Time (DST) is a common practice in the world. During some time in spring and summer, countries tend to skip one hour and change their clocks in order to save daylight and electricity. In Europe, it’s called Central European Summer Time (CEST)  or Central European Daylight Time (CEDT). Unlike CET, CEDT is 2 hours ahead of UTC (UTC + 2:00). Most European Union members have adopted the SummerTime which is observed from the last Sunday of March and to the last Sunday of October. However, some countries use CET all year. 

How To Convert CET to Other Time Zones?

With the advancement of technologies, conversion between time zones has become relatively simple. Probably, the easiest way to convert CET to other time zones is to turn on the location and use your smartphone or laptop. There are a number of online tools on the internet that can help you convert CET to your preferred time zone. Our Time Zone Converter is one of such kinds of instruments. 

However, if you’re interested in time zone differences and want to know how Central European Time relates to other time zones, the first thing you should remember is that it’s one hour ahead of the Coordinated Universal Time (UTC). Therefore, it’s the same as Irish Standard Time, West Africa Time, British Summer Time, or Western European Summer Time. Use the following guide to find out how to convert CET to other time zones:

Therefore, to convert IST to CET you should add 4 hours; In order to convert CET to EST you should subtract 5 hours; To convert CET to MST you should subtract 7 hours; in order to convert CET to PST you should subtract 8 hours, and in order to convert CET to CST you should subtract 8 hours as well. 

Major Territories in CET Time

After World War II, many countries implemented Central European Time and switched their clocks to CET. However, some countries like Portugal changed the time system afterward. Today CET is used in most parts of Europe and in Africa, specifically in South Africa. In Total, 25 countries observe CET either entirely or alongside Central European Summer Time. Below we will provide the list of all the territories that use Central European Time and sort them by continents. 

Europe

All the following European countries use Central European Time in the fall and winter and switch to Central European Summer Time in spring and summer.

  • Albania
  • Andorra
  • Austria
  • Belgium
  • Bosnia-Herzegovina
  • Croatia
  • Czech Republic
  • Denmark
  • France
  • Germany
  • Gibraltar
  • Holy See/Vatican City
  • Hungary
  • Italy
  • Kosovo
  • Liechtenstein
  • Luxembourg
  • Macedonia
  • Malta
  • Monaco
  • Montenegro
  • Netherlands
  • Norway
  • Poland
  • San Marino
  • Serbia
  • Slovakia
  • Slovenia
  • Spain – (except the Canary Islands)
  • Sweden
  • Switzerland

Africa

There are three African countries that observe CET and all of them are located in North Africa. They also call their time zone West Africa Time (WAT). 

  • Algeria
  • Morocco
  • Tunisia

Difference Between CET and CEDT

Daylight Saving Time (DST) frequently gives rise to confusion. Many people aren’t sure when exactly it starts in the current year when it ends, how it relates to standard time, and what its purpose is after all. Considering this, it’s not surprising that people also find it hard to understand the difference between CET and CEDT. In this section, we will compare these two time zones.

CET stands for Central European Time. The standard Time zone is usually used either during the entire year or in fall and winter. It depends on whether countries observe Daylight Saving Time (DST). In the case of territories where Daylight Saving Time is used, CET starts on the last Sunday in October and continues to the last Sunday in March. 

On the other hand, CEDT stands for Central European Daylight Time or Central European Summertime (CEST). CEDT is observed in spring and summer, specifically from the last Sunday in March to the last Sunday in October. All countries in the Central European Time Zone observe CEDT except Algeria and Tunisia. During this time, clocks are advanced by one hour. Therefore, the offset of CEDT is UTC + 2:00 instead of UTC + 1:00. The changeover usually takes place either at 2 or 3 a.m. 

FAQ about Central European Time

Where is the CET time zone?

CET time zone is the 15th meridian east time zone, the central axis for UTC+01:00. It covers the territories in Europe and North Africa. Central European Time is used in the following 35 countries: Albania, Andorra, Austria, Belgium, Bosnia and Herzegovina, Croatia, Czech Republic, Denmark, France, Germany, Hungary, Italy, Kosovo, Liechtenstein, Luxembourg, Malta, Monaco, Montenegro, Netherlands, North Macedonia, Norway, Poland, San Marino, Serbia, Slovakia, Slovenia, Spain (except the Canary Islands), Sweden, Switzerland, and Vatican City. 

Is CET the same as GMT?

No, Central European Time (CET) and Greenwich Mean Time (GMT) are two different time zones. CET is one of the 24 longitudinal time zone divisions of the Earth. On the contrary, GMT is the time zone reference point. CET is one hour after GMT which is the same as UTC + 1 hour.

Is CET always 1 hour ahead of GMT?

Yes, Central European Time is always one hour ahead of Coordinated Universal Time (UTC). Consequently, the time offset from UTC is UTC+01:00. However, some countries in the Central European Time Zone observe Summer Time (CEST). During the Central European Summer Time, the offset is UTC+02:00.

What is CET time in the USA?

Since the USA uses several different time zones, CET can be converted in different ways based on the territory. CST is 5 hours ahead of Eastern Standard Time (EST), 7 hours ahead of Mountain Standard Time (MST), 8 hours ahead of Pacific Standard Time (PST), and 8 hours ahead of Central Standard Time (CST).

MST – Mountain Standard Time

Everyone knows which time zone they live in but not many people are aware of the concept of time zones. Sometimes people just think that having so many time zones is not necessary as it brings confusion in the process of traveling or communicating with people from different countries. However, actually having multiple time zones has its purpose, and it’s very convenient for different areas to keep in touch at the right time. 

With the advancement of technologies,  the time zones of various countries have become vital for clear communication. Probably you’ve heard phrases such as Mountain Time Zone, Standard Time, or Daylight Time but if you feel confused about the way these different time zones work, then you’re at the right place! 

Mountain Standard Time (MST) is one of the major time zones in the world which is used in North America. It’s observed during standard time and is 7 hours behind UTC. In this article, we will explain what MST time is and review its brief history to help you understand the purpose of this time zone. We will also explain the mechanism of MST time and help you understand the ways to convert it to different time zones. In the end, you’ll have a clear understanding of the territories that belong to the Mountain Time Zone and acknowledge the difference between Mountain Standard Time and Mountain Daylight Time. 

MST Mountain Standard Time

What Is MST Time?

Mountain Standard Time or MST as it’s often referred to is one of the time zones that is generally used in the United States. Specifically, it’s the second westernmost time zone in the United States and Canada and it’s also used by some territories of Mexico. 

MST stands out from other time zones by the fact that it’s the least populated time zone in the US. Even though most territories that belong to the Mountain time zone are located in the United States, these areas are inhabited by the least number of people, compared to other time zones. Mountain Standard Time spans from northern Canada and goes to Mexico near the Equator which is an imaginary line that divides the earth into two, northern and southern hemispheres. 

MST covers 13 states of the US. While some of the states base their daily routines completely on Mountain Time, others also observe different time zones in some cities and places. MST is also observed by 5 provinces of Canada. 

In order to have a more clear insight about the location of the Mountain Time Zone, you should know that it shares a border with Central Standard Time in the east and Pacific Standard Time in the west. These two time zones are also used in North America.  

MST is seven hours behind the Coordinated Universal Time (UTC). Therefore, in the territories that observe Mountain Time, the standard time is UTC – 07:00.

Brief History of MST

The history of time goes back to ancient times. Ever since human beings have existed, we have used different methods of measuring time. Everything started by observing the natural world. More than 30 000 years ago, people used to tackle time based on the position of the moon and stars. Surprisingly, measuring time by the position of the sun was still present in the 20th century. A lot has changed since then and today we have a 24-hour time system and various time zones. Mountain Standard Time is one of them. Even though today’s time system is rather effective, time still isn’t as objective as it seems. And probably, it never will be.

Nowadays there are 24 time zones in the world that start from the place where Greenwich Observatory in England is located. Different time zones were first introduced in the 19th century when scientists realized that standardization of time would make communication and traveling less complicated. It was mainly because of technological changes.

Although we don’t know who exactly invented Mountain Standard Time, we do know the name of a man who proposed the system of today’s worldwide time zones. In fact, in 1878 Scottish Canadian engineer and inventor Sir Sandford Fleming suggested that the world be divided into 24 time zones. The reason is that the earth rotates once every 24 hours and there are 360 degrees in total. The first industry that started using the new timezone system was the railroad industry. It was the only way to avoid confusion about the schedules of trains that traveled across various time zones. 

US states started using Mountain Standard Time and other time zones such as Pacific, Central, and Eastern time zones in 1895. Today using the current system of time zones is mandatory for all states with the law of the Standard Time Act issued in 1918 by congress. 

How Does MST Work?

Mountain Standard Time (MST) is a standard time, meaning that it’s observed in the period of the year when Standard Time is used instead of Daylight Time. Specifically, it’s observed from the first Sunday in November to the second Sunday in March. Mountain Standard Time is 7 hours behind Coordinated Universal Time (UTC). Generally, it’s used in North American territories. Since Daylight Saving Time (DST) is not used in some British Columbian areas, such as Creston, Fort Nelson, Fort St. John, and Dawson Creek, Mountain Standard Time is in effect all year. 

People often wonder where the name “Mountain” originates from. In fact, this time zone is named after its location – MST includes territories of the US and Canada in or near the Rocky Mountains. These mountains are located entirely into MST and range from northwestern Canada to New Mexico.

MST is based on the mean solar time at 105° W. Consequently, it’s also seven hours behind the Greenwich Mean Time (GMT). Mountain Standard Time has been in global use since 2007.

How To Convert MST to Other Time Zones?

Now as you already know the history of introducing Mountain Standard Time, it’s time to find out how to convert it to different time zones. Actually, the mechanism of MST conversion is just the same as other time zones. The first thing you should do is to remember its relation to the Coordinated Universal Time. As we already said, MST is 7 hours behind UTC. Therefore, you can calculate the UTC and use online time zone converters in order to determine the exact time in any location on the earth. 

However, if you want to learn the mechanism of converting MST to other time zones and are eager to do it yourself, keep the following facts in mind:

  • MST is 1 hour ahead of Pacific Standard Time (PST).
  • MST is 1 hour behind Central Standard Time (CST).
  • MST is 2 hours behind Eastern Standard Time (EST).

Considering this, in order to convert MST to PST, you need to subtract 1 hour; In order to convert MST to CST, you need to add one extra hour and in order to convert MST to EST you should add 2 hours. 

Major Territories in MST Time

Mountain Standard Time is generally observed only in the continent of North America. However, it doesn’t cover all countries and all territories. In fact, MST is used in 3 countries in America: the United States, Canada, and Mexico.  Mountain Standard Time is usually referred to as Mountain Time (MT) in most parts of the United States and Canada. The majority of territories that are in the Mountain time zone observe daylight time as well. 

The term MST referred to the Rocky Mountains that range from British Columbia to New Mexico. While Canadians and Americans usually use the name “Mountain Standard Time ”, in Mexico, this time zone is known as the Tiempo de la montaña or zona Pacífico. Here are the exact territories that observe Mountain Standard Time:

The United States

In the US, MST is observed entirely in six states. Two states observe MST and Pacific Time zones in different regions and five states observe MST and Central Standard Time (CST) in different regions. 

  • Arizona (Navajo Nation)
  • Colorado
  • Idaho (except western counties)
  • Kansas (only western counties)
  • Montana
  • Nebraska (only western counties)
  • New Mexico
  • North Dakota (South-Western part)
  • Oregon – (Malheur county)
  • South Dakota – (only western counties)
  • Texas (some western counties)
  • Utah
  • Wyoming

Canada

In Canada, only one province is entirely in the MST and it’s Alberta. One province and one territory observe both MST and Pacific Time and the other one province and one territory observe MST and Central Standard Time. 

  • Alberta
  • British Columbia (Cranbrook, Golden, Invermere)
  • Northwest Territories
  • Nunavut (Kugluktuk, Cambridge Bay)
  • Saskatchewan (Lloydminster)

Mexico

  • Baja California Sur
  • Chihuahua
  • Nayarit (except for the Bahía de Banderas municipality).
  • Sonora 
  • Sinaloa
  • Revillagigedo Islands (Colima) (Isla Socorro, San Benedicto Island and Roca Partida)

MST vs MDT – Comparison

Since MST and MDT are both in the Mountain Time Zone, people often get confused about these two time zones. However, after understanding the purpose of Daylight Saving Time, everything gets clear. Daylight Saving Time (DST) is a common practice of advancing clocks by one hour during spring and summer in order to save daylight. Territories that use DST, use both Standard Time and Daylight Time. Therefore, if a state or city uses MDT it means that they are observing Daylight Saving Time.

MDT is an abbreviation of Mountain Daylight Time, whereas MST refers to Mountain Standard Time. Both MST and MDT are in the same time zone which is Mountain Time Zone (MT). They are used by the same territories but some places observe MST throughout the whole year and don’t use MDT. 

The main difference between these two time zones is that they differ in one hour. Specifically, MDT is 6 hours behind the Coordinated Universal Time (UTC), while MST is 7 hours behind UTC. That’s because of the switch to Daylight Saving Time. In fact, MDT starts from the second Sunday in March and continues to the first Sunday in November. Mountain Time Zone territories observe MST during the remaining days of the year. 

So, here are the main differences between MST and MDT:

  • MST is Standard time while MDT is Daylight time,
  • MST is used in the fall and winter while MDT is used in spring and summer.
  • MST is UTC – 7:00; MDT is UTC – 6:00
  • The difference between MST and MDT is 1 hour.

FAQ about Mountain Standard Time

What are MST hours?

Mountain Standard Time (MST) is 7 hours behind Coordinated Universal Time (UTC). It’s one hour behind Eastern Standard Time (EST), one hour behind Central Standard Time (CST), and one hour ahead of Pacific Standard Time (PST).

Where is the MST time zone?

Mountain Standard Time is observed in North America. Specifically, the Mountain Time Zone spans from northern Canada and goes to Mexico near the Equator. It covers some territories of the United States, Canada, and Mexico. MST covers all the territories from British Columbia to New Mexico that belong to the Rocky Mountains. 

Why is it called Mountain Standard Time?

The term Mountain Standard Time refers to the Rocky Mountains, also known as the Rockies. It’s a mountain range that stretches from the northernmost part of western Canada to New Mexico in the southwestern United States. The Rocky Mountains is the largest mountain system in North America. All territories in this time zone observe Mountain Time (MT). 

Is Mountain Time the same as Pacific time?

Pacific Standard Time (PCT) is 8 hours behind Coordinated Universal Time (UTC−08:00), while MST is 7 hours behind UTC. Therefore, they aren’t the same and The Mountain time zone is one hour ahead of the Pacific time zone. However, both MST and Pacific Daylight Time are UTC – 07:00. 

How many hours is MST from EST?

Mountain Standard Time is 2 hours behind Eastern Standard Time (EST). Therefore, in order to convert EST to MST, you should add two hours. EST is UTC−05:00. 

What is the MST time zone in the USA?

In the United States, Mountain Standard Time extends to the entire area of the following states: New Mexico, Wyoming, Utah, Colorado, and Montana. Also, it’s observed by some parts of Idaho, Oregon, North Dakota, South Dakota, Nebraska, Texas, Kansas, and Nevada.

CST – Central Standard Time

If you live somewhere around the continents or North or South America, you probably often hear the phrase Central Standard Time and know the way this time zone works. But even if you live far away, understanding the time standard and various time zones can be useful. 

With the digitalization of the world, more and more people started working remotely. Consequently, time zone differences are one of the most widely discussed topics in today’s workplace. No one wants to skip online meetings as a result of confusion about time zones. Nowadays it’s very common to work together with people who live oceans apart from you. Therefore, getting to know more about time zones has become vital for efficient communication and collaboration with people who live in different countries. The same applies to people who enjoy traveling. No one wants to miss a plane just because they couldn’t understand the time zone difference.

In this article, we’re going to provide an in-depth overview of Central Standard Time (CST) and clear up the confusion regarding it. We’ll explain what Central Standard Time is, how it works, review its brief history and territories that observe CST. Besides, we will try to teach simple ways to convert CST to different time zones and compare it to Central Daylight Time (CDT) as well. Let’s get started!

CST Central Standard Time

What Is CST Time?

Central Standard Time or CST as it’s often called is one of the major time zones that is six hours behind the Coordinated Universal Time (UTC). This time zone is used by some parts of countries located in North and South America such as Canada, the United States, and Mexico, as well as some parts of the Eastern Pacific Ocean and Caribbean islands. In total, CST applies to 9 countries. The largest city in the Central Time Zone is Mexico City which is also the largest metropolitan area in North America.

CST is a part of the Central Time Zone which consists of Central Standard Time and Central Daylight Time during different seasons. It’s 6 hours behind the Greenwich Mean Time (GMT) during winter and the fall and 5 hours behind during the spring and summer months. However, the difference between the various time zones to each other is usually expressed in terms of UTC instead of GMT. While some countries in the Central Time Zone use Daylight Saving Time and switch to Central Daylight Time during summer, others remain in CDT throughout the entire year. The Canadian province of Saskatchewan is an example of a territory in the Central Time Zone that observes CST all year. 

Brief History of CST

Before we explain the exact mechanism of how CST works, let’s review a brief history of Central Standard Time and find out a bit more about its origins. In today’s fast-paced world, it’s hard to imagine not being able to determine the exact time of a day. But there was a period in worldwide history when people didn’t mind not knowing the exact time. In fact, just two centuries ago, people used to determine the time according to the position of the sun. They set their clocks at noon based on the period when the sun reached the highest position in the sky. As a result, even cities in the same time zone had different times. 

The difference in time was especially confusing regarding train schedules. It was almost impossible to determine the exact time of departing or arriving as scheduled varied across different train stations. As a result, over time, communities realized that the US states needed a more accurate system of the time.

The development of the global time system originates in 1845 when Sir Sandford Fleming introduced the idea of standard time. He was a Scottish-Canadian foremost railway construction engineer, scientist, and inventor. He came up with the idea of setting standard time after spending a night in the railway station as a result of time confusion. This was the time when he realized that the global time system could solve the existing problems in the railway industry. Fleming is the man whose system of standard time is used even today. 

The first country that started observing standard time was Great Britain. In 1847 British railways switched to standard time from local mean time. The first railway that adopted London time was the Great Western Railway. The North American railway system adopted a standard time decades later, in 1883. Many things have changed afterward and today using Central Standard Time is already common practice in various U.S. states or territories in Canada and Mexico. 

How Does CST Work?

In order to travel in various time zones without confusion, people should understand the way different time zones work. While it seems like a complicated process at a first glance, actually it’s much easier. The most important thing about Central Standard Time to remember is that it’s 6 hours behind the Coordinated Universal Time (UTC). Also, this time zone is usually used in North America and Central America during standard time (in fall and winter). 

CST is the second easternmost time zone in the United States, while it’s the third one in Canada. The time zone spans from northern Canada in the south to Costa Rica near the Equator, an imaginary line around the middle of a planet that divides the earth as the North Pole and the South Pole. In North America, it shares borders with EST and MST to the east and west accordingly. 

CST is usually used in the fall and winter on territories that are in the Central Time Zone. It’s used from the first Sunday in November to the second Sunday in March. The most confusing thing about Central Time is that it is usually 6 hours behind UTC but when Central Time Zone territories are in the period of Daylight Saving Time (DST), CST is not in effect. During this time Central Daylight Time (CDT) is used instead which is 5 hours behind UTC. CDT works between mid-March and early November. 

How To Convert CST to Other Time Zones?

The key factor about the conversion of CST to other time zones is its relation to UTC. Usually, people determine the time based on the Coordinated Universal Time and use UTC to convert to different time zones. As you already know, Central Standard Time is UTC – 6 hours. However, the process of determining the time for your destination places will et much easier if you remember the following things about the connection of CST and other major time zones: 

  • Central Standard Time is 1 hour behind Eastern Standard Time (EST).
  • Central Standard Time is 1 hour ahead of Mountain Standard Time (MST).
  • Central Standard Time is 2 hours ahead of Pacific Standard Time (PST).

Accordingly, in order to convert CST to EST, you need to add one hour; In order to convert CST to MST, you need to discount one hour; In order to convert CST to PST, you need to discount two hours. 

But if you still feel confused and don’t know the exact time zone of your own or destination country or don’t fully understand the mechanism of converting CST to other time zones, you can easily reach out to our Time Zone Converter. Today online time zone tools are very useful to find out time whenever you want and wherever you are. 

Major Territories in CST Time

In order to convert time correctly, first, you need to know the territories that are located in specific time zones. The Central Time Zone covers the continents of North America and South America. Specifically, it’s used in the United States, Mexico, Central America, some parts of Canada, some Caribbean Islands, and in the Eastern part of the Pacific Ocean. However, Canada, as well as the USA and Mexico use various time zones, including Mountain Time, Pacific Time, Alaska Time, Hawaii-Aleutian Standard Time, and more, not to mention standard and daylight times. 

The reason is that such big countries like the United States or Canada are located in more than one time zone. Therefore, different territories observe different times. Specifically, Central Standard TIme covers 20 states in the US (partly or entirely) and three provinces in Canada. It’s also used in Mexico and Central America. Here is the entire list of territories that observe CST.

North America

  • Alabama
  • Arkansas
  • Florida (partly)
  • Illinois
  • Indiana (partly)
  • Kansas (partly)
  • Kentucky (partly)
  • Louisiana
  • Michigan (partly)
  • Minnesota
  • Mississippi
  • Missouri
  • Nebraska (partly)
  • North Dakota (partly)
  • Oklahoma
  • South Dakota (partly)
  • Tennessee (partly)
  • Texas 
  • Wisconsin

Canada

  • Manitoba
  • Ontario (partly)
  • Saskatchewan (partly)

Mexico

  • Aguascalientes
  • Campeche
  • Chiapas
  • Coahuila
  • Colima
  • Distrito Federal
  • Durango
  • Guanajuato
  • Guerrero
  • Hidalgo
  • Jalisco
  • León
  • Michoacán
  • Morelos
  • México
  • Nuevo León
  • Oaxaca
  • Puebla
  • Querétaro
  • Quintana Roo
  • San Luis Potosí
  • Tabasco
  • Tamaulipas
  • Tlaxcala
  • Veracruz
  • Yucatán
  • Zacatecas

Central America

  • Belize
  • Costa Rica
  • El Salvador
  • Guatemala
  • Honduras
  • Nicaragua

Comparison of CDT vs CST

Even though people often confuse CST with CDT, if you understand the purpose of Daylight Saving Time (DST), everything will get back to normal. How so? What does DST have to do with CDT or CST? Let’s start from the beginning. 

CST stands for Central Standard Time, while CDT is an abbreviation of Central Daylight Time. The main difference between them is that CST is an hour behind CDT. And remember that these two time zones are never used together.

Daylight Time is usually used during the spring and summer. Its main purpose is to extend daylight and save energy. However, not all countries observe Daylight Saving Time. The same applies to Central Time. Some territories that observe Central Standard Time use DST from the second Sunday of March and to the first Sunday of November. During this period, the main time zone for Central Time Zone territories is CDT instead of CST. Central Standard Time is used during the remaining period of the year. 

So, here are the differences between CDT and CST:

  1. CDT is 5 hours behind the UTC; CST is 6 hours behind the UTC. 
  2. CDT is used during the summer and spring. CST is used during the fall and winter.
  3. CDT is a particular time zone that observes Daylight Saving Time; CST is a particular time zone that observes Standard Time. 

Therefore, both time zones are used on the same territories but during different seasons. Consequently, the difference between CDT and CST is 1 hour. 

FAQ about Central Standard Time

Which months does CST cover?

Central Standard Time usually continues from the first Sunday in November to the second Sunday in March. Therefore, it covers November, December, January, February, and March. If a territory doesn’t observe Central Daylight Time, then CST also extends on the remaining months (April, May, June, July, August, September, and October).

Which countries observe Central Standard Time?

The Central Time Zone covers the continents of North and South America. The countries that observe CST are located in Central America, South America, North America, and Oceania. In Central America, this zone includes the countries of Belize, Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica. In South America, CST is observed by the Ecuadorian province of Galápagos. In Oceania, CST is used by the Chilean Easter Island. Certain parts of Canada and the United States also observe CST. 

Is CT the same as CST?

No. Central Time (CT) is a time zone that includes Central Standard Time (CST), as well as Central Daylight Time (CDT). On the contrary, CST has nothing to do with daylight time. Central Time isn’t static. It switches between

CDT and CST. But CST always remains the same. Therefore, sometimes CT and CST are the same but sometimes CT differs from CST by one hour. 

What is the current CST time in the USA?

Central Standard Time is always 6 hours behind the Coordinated Universal Time (UTC−06:00). But US time varies from state to state. Use Time In World Cities to find out the exact time in different parts of the United States at a given moment. 

How to convert UTC to CST?

Coordinated Universal Time is 6 hours ahead of Central Standard Time. Therefore, in order to convert UTC to CST, you need to subtract one hour. 

EDT – Eastern Daylight Time

Many people don’t understand the concept of a time zone. They don’t know much about the different time zones in the world. Of course, everyone knows what time zone they are in. However, how much do you know about time zone differences, and how did scientists come up with time zones in the first place? And, where does the EDT – Eastern Daylight – time zone stand in all of this?

The reality is that time zones are extremely important to everyone, whether we realize it or not. They greatly influence social and commercial activity and have an influence over military communications and operations. Just think about it: if you are based in, say, London, Paris, or Madrid, but you work or communicate with someone who lives in a city that observes the Eastern Daylight Time, you’ll need to know exactly what time is it over there to make sure you don’t call the other person at odd hours.

So, let’s take a look at what the EDT time zone is and how it relates to the other time zones on Earth. In addition, we will list the most important countries and the major cities that are in EDT to make it easier. Curious fact: it is important to note that these countries and cities are not in the EDT time zone all year round, because some of them observe Daylight Saving Time, which means they enter another time zone during the summer months. It may sound confusing at first, but understanding how time zones work and when do countries switch to Daylight Saving Time makes it easier to figure out. And top it all off, you’ll also find a list of fun facts about time zones towards the end of this article.

What Exactly Is a Time Zone?

First things first: you are probably wondering what a time zone really is. Let’s explain it in simple terms. You are probably aware that not all countries on Earth observe noon at the same time. It would be impossible because the Earth is a rotating sphere, and only half of it faces the Sun during the day. Because the Earth rotates, various countries observe noon at different hours throughout the day. 

To coordinate a time and to help people, industries, governments, and businesses, the Earth was split into 24 time zones. The ideal situation is to have the sun at its highest point in the sky when it is noon, that is when crossing the meridian. If we have just one time zone, it would not be possible because the Earth rotates 15 degrees every hour. It was then agreed that a system of multiple time zones be adopted. In this system, the world is divided into 24 15-degree sections and clocks are set according to each time zone, with each time zone having a difference of one hour to the next zone. This will make all the people within a particular time zone set their clock the same way.

For instance, in the United States, there are four time zones. They include the Eastern, Central, Mountain, and Pacific. To have an idea of how they are related: when it is noon in the Eastern time zone, it is 11 a.m. in the Central time zone, 10 a.m. in the Mountain time zone and 9 a.m. in the Pacific time zone. It is important to note that all time zones are measured from a starting point centered at England’s Greenwich Observatory. This point is known as the Greenwich Meridian or Prime Meridian. The time at the Greenwich Meridian is known as Greenwich Mean Time (GMT). The Eastern time zone in the United States is designated GMT-5. This means that when it is noon in the Eastern time zone, then the time is 5 p.m. at the Greenwich Observatory. 

All countries and cities in a time zone observe the same time. There is no difference in time, even if the countries are thousands of miles apart. Different parts of the world enter and exit daylight at different times, so splitting the world into 24 time zones makes a lot of sense. It’s like grouping areas that are in daylight together. 

All time zones are now regulated after Coordinated Universal Time (UTC), which in 1972 became the world’s time standard replacing the GMT. Although the GMT is not considered a standard anymore, it still belongs to one of the 24 time zones of the world. The GMT is especially used by many African countries, in the UK (winter season) and in Western Europe.

The Coordinated Universal Time (UTC) is so-called since it has become the standard by which all the time zones are based. And contrary to what is generally believed, UTC is not a time zone. It is the standard by which all the world timing systems have adopted, synchronizing their local clocks with it. The various time zones are simply designated by the hourly difference between UTC.

The UTC time standard has two main components: the International Atomic Time (TAI) and Universal Time (UTI). TAI is a scale that helps determine the speed at which clocks should tick. It is found by combining the time of more than 200 atomic clocks located worldwide. It is very accurate. On the other hand, UTI is determined by the Earth’s rotation. This is why it is sometimes called astronomical or solar time. Often, timekeepers use to measure the length of a single day on the planet using the UTI.

Because of the International Atomic Time (TAI) and the Universal Time (UTI), Coordinated Universal Time is used to synchronize clocks across the various countries all over the world, and across 24 different time zones.

What is EDT?

So what does that have to do with EDT specifically?

Now that you know exactly how time zones work, it’s time to take a closer look at the Eastern Daylight Time zone. This one is a curious one because it isn’t static: regions in this time zone switch to another one when it’s time to move clocks forward or backward to Daylight Savings. Curiously, EDT isn’t just observed in North America: if you drew a vertical line down from Connecticut, you’d notice EDT also covers parts of Central and South America.

Brief History of EDT

Before we discuss the history of Eastern Daylight Time, it’s important to say a few words about the origins of Eastern Standard Time (EST). Observing EST goes back to the 19th century and is connected with the need for the trains to have standardized time. The first country that started using EST was Great Britain. The country started using EST on December 1, 1847, in the railway system. However, the majority of British public clocks observed GMT until 1855. 

A few decades later, on November 18, 1883, the United States followed Great Britain and started using a standard time in the railroad system. It included not only Eastern Standard Time, but also Central, Mountain, and Pacific. On November 18, 1883, America’s railroads began using a standard time system involving four time zones, Eastern, Central (CDT), Mountain (MST), and Pacific (PCT).

However, the United States began observing Daylight Saving Time for the Eastern time zone much earlier. Specifically, DST was introduced in 1966 by the Uniform Time Act. But the country started saving daylight time only in 1987. 

Unlike DST, Eastern Daylight Time doesn’t have a long history. In fact, daylight saving time was extended to other U.S. time zones in 2005 by the Energy Policy Act, and observing EDT started in 2007. Since then, the states and cities that observe Eastern Standard Time (EST) change their clocks from 2 a.m. to 3 a.m. on the second Sunday in March and return from 2 a.m. to 1 a.m. on the first Sunday in November. That’s the period when EDT is used. 

How Does EDT Work?

Understanding the mechanism of EDT is nothing difficult for those who are aware of the purpose of Daylight Saving Time. Just like Mountain Daylight Time (MDT) or Central Daylight Time (CDT), Eastern Daylight Time (EDT) is used only throughout a certain period of the year. EDT is observed by the countries and states that normally use Eastern Standard Time. It’s the easternmost time zone in the United States and the second Easternmost time zone in Canada.

Specifically, EST is observed by 23 US states, three provinces of Canada, and the Caribbean. All these territories change their clocks by one hour in order to save daylight. In the North American time zone, the use of EDT starts from the second Sunday in March and continues until the first Sunday in November. During the remaining months, these territories use EST. 

Therefore, both EST and EDT make up Eastern Time (ET) together. 

The exact way how EDT works is the following: in order to observe “Summer Time” or DST territories that usually use EST change their clocks on the second Sunday in March, at 2 a.m. and advance them to 3 a.m. This one-hour “gap” is returned back to normal on the first Sunday in November, at 2 a.m. when the clocks are changed to 1 a.m. That’s the entire philosophy of EDT, as easy as that! 

How to Convert EDT to Other Time Zones?

When it comes to time zones, getting to know how to convert one time zone to another is one of the most frequent issues especially for travelers. If you travel across various time zones, you need to prepare your body for the confusing feeling of jetlag and set your plans properly. Understanding the difference between time zones is the easiest way for this. 

So, if your country or the destination country is in the process of observing daylight time and you want to convert Eastern Daylight Time to other time zones, pay attention to the list below:

  • EDT is 1 hour ahead of Central Daylight Time (CST).
  • EDT is  2 hours ahead of Mountain Daylight Time (MDT).
  • EDT is 3 hours ahead of Pacific Daylight Time (PDT).

Consequently, in order to convert EDT to CDT, you need to discount one hour; In order to convert EDT to MDT you need to discount two hours, and in order to convert EDT to PDT you need to discount three hours. 
But if you still feel confused about the time conversation, just go ahead and use online resources like worldclock.com and avoid the rather puzzling process of determining the exact time of the destination country.

Major Countries in EDT Time Zone

Now that you know what a time zone is, what EDT is, and how it related to Coordinated Universal Time, we also need to cover the seasonal Daylight Saving Time changes.

Daylight Saving Time is the system of setting the clocks forward one hour from standard time (the local time in a country or region when daylight saving is not in use) during the summer months and back again in the fall. This is to ensure better use of natural daylight. Established in the early twentieth century, the system of daylight saving is now widespread over 70 countries worldwide, but whether a country observes DST or not is its own choice. Unlike time zones, Daylight Savings is something countries agree on, rather than a universal global standard. Some countries adhere to seasonal DST changes, others do not, and others still (Australia, for example) have different regions which observe or ignore the DST on their own.

Understanding DST is important when talking about EDT because Eastern Daylight Time is directly affected by DST. What this means is, whenever you’re trying to reach someone in, say, Florida, don’t just check what the current time in EDT is – keep in mind it may be an hour ahead or behind depending on the season.

Now, it’s time to take a look at the major countries that are in the EDT time zone. The following states in North America are in the EDT time zone:

  • Connecticut
  • Delaware
  • District of Columbia
  • Florida – Southern/Eastern parts Show
  • Georgia
  • Almost all of Indiana
  • Kentucky
  • Maine
  • Maryland
  • Massachusetts
  • Michigan – most except these western counties Show
  • New Hampshire
  • New Jersey
  • New York
  • North Carolina
  • Ohio
  • Pennsylvania
  • Rhode Island
  • South Carolina
  • Tennessee – eastern counties Show
  • Vermont
  • Virginia
  • West Virginia

There are also three Canadian territories that are in the EDT time zone during the summer months: Nunavut, Ontario and Quebec. Also, there are two Caribbean territories that are in the EDT time zone in the summer months: Bahamas and Haiti. In South America, we have Colombia, Ecuador, Peru and some parts of Brazil. Other countries that are in the EDT time zone during parts of the year include Mexico, Panama, Jamaica, Haiti, and Cuba. As you can notice, there are a lot of relatively large territories in this time zone. Although there are no exact figures, the number of people living in the Eastern Daylight Time zone is in the hundreds of millions. And yes, all of these people are observing the exact same time, which is UTC-04:00. There is no difference in time between New York and Cuba!

Major Cities in the EDT Time Zone

Because Eastern Daylight Time covers such a large area, it is only natural to have a lot of major metropolitan areas in it. Here are some of the largest cities in the EDT time zone:

  • Washington, D.C.
  • Atlanta, Georgia
  • Baltimore, Maryland
  • Barrie, Ontario
  • Bogotá, Colombia
  • Boston, Massachusetts
  • Burlington, Vermont
  • Charleston, West Virginia
  • Charlotte, North Carolina
  • Cincinnati, Ohio
  • Cleveland, Ohio
  • Columbia, South Carolina
  • Columbus, Ohio
  • Detroit, Michigan
  • Grand Rapids, Michigan
  • Greater Sudbury, Ontario
  • Guayaquil, Ecuador
  • Hamilton, Ontario
  • Havana, Cuba
  • Indianapolis, Indiana
  • Iqaluit, Nunavut
  • Jacksonville, Florida
  • Kingston, Jamaica
  • Knoxville, Tennessee
  • La Paz, Bolivia
  • Lima, Peru
  • London, Ontario
  • Louisville, Kentucky
  • Manchester, New Hampshire
  • Medellín, Colombia
  • Miami, Florida
  • Montreal, Quebec
  • Nassau, Bahamas
  • New York, New York
  • Orlando, Florida
  • Oshawa, Ontario
  • Panama City, Panama
  • Philadelphia, Pennsylvania
  • Port-au-Prince, Haiti
  • Portland, Maine
  • Quebec, Quebec
  • Quito, Ecuador
  • Richmond, Virginia
  • Rochester, New York
  • Springfield, Massachusetts
  • Thunder Bay, Ontario
  • Toledo, Ohio
  • Toronto, Ontario
  • Trenton, New Jersey
  • Wilmington, Delaware
  • Windsor, Ontario
  • Worcester, Massachusetts

Difference Between EDT and EST

People often get confused by the similarities of EDT and EST because they only differ by one letter. The most obvious thing about these two time zones is that both of them represent Eastern Time (ET). But what’s the difference between EDT and EST?

Let’s start with EST. It’s short for Eastern Standard Time, a time zone that is used when observing standard time and is five hours behind Coordinated Universal Time. Therefore, EST is UTC – 5 hours. This time is usually used by North Americas in the fall and in winter.

As we already pointed out, EDT is an abbreviation of Eastern Daylight Time. It’s used by North American territories that observe daylight saving time.  EDT is four hours behind Coordinated Universal Time (UTC – 4 hours). Usually, EDT is used during the spring and summer which is why it’s also called “Summer Time”. 

So, here are the main points about EDT vs EST:

  • EDT and EST are time zones under the Eastern Time Zone (ET).
  • Both EDT and EST are used in the 21 North American time zones, including 9 time zones in the USA including Alaska and Hawaii, and 4 standard time zones in the mainland. 
  • EST is 5 hours behind the Coordinated Universal Time and EDT is four hours behind. So, EST is UTC-5, EDT is UTC-4. 
  • Both EDT and EST are used in the same areas of the United States and Canada but in different seasons. Specifically, EST is used during fall and winter, while EDT is used in the spring and summer. 

Now you probably acknowledge the power of Daylight Saving Time on various time zones and hopefully, when it comes to the differences between EST and EDT, you won’t get confused anymore!  

Fun Facts About Time Zones

Now that you know what the EDT time zone is, how it relates to Coordinated Universal Time (UTC) and what countries and cities it covers, let’s take a look at some of the most interesting and fun facts about time zones:

  • UTC time coordinates time in all time zones; this is why the UTC offset was created. However, UTC is being periodically adjusted itself using leap seconds, because the slowing rotation rate of the Earth is making UTC drift away from atomic clock time every year.
  • Emails coming from a sender who is in the EDT time zone will have the -0400 email time zone indicator in their headers. However, the sender may not be in EDT time because there are other time zones that use the UTC-04:00 offset during some parts of the year.
  • EDT is a daylight savings time, so it used only during summer months. The rest of the year, the time zone is Eastern Standard Time (EST), which is UTC-05:00. Keep that in mind when trying to call someone who lives in New York!
  • GMT is the time zone that follows UTC time (it has no UTC offset). However, GMT is GMT+01:00 during summer months in most parts of the time zone. This happens because the United Kingdom observes Daylight Savings Time.
  • Daylight savings time is both an ancient and a recent invention. Historical records show that romans observed changes in daylight during the summer months and adjusted their water clocks accordingly; in recent history, ideas about daylight saving time started appearing in the nineteenth century and were finally materialized in the early 1920’s due to Germany’s effort to save energy during the war. Eventually, moving the clocks forward and back to enjoy more daylight during the summer days became the norm in most Western countries.
  • Although Daylight Saving Time is observed in over 70 countries around the world, not everyone is happy about it. In Europe, surveys show most Europeans would like to ditch DST altogether, and in the United States, there is a movement called Lock the Clock lobbying for abolishing the seasonal DST changes.
  • Perhaps unsurprisingly, not all countries observe Daylight Savings Time. Examples include most of Africa, Argentina, Peru, and even parts of Australia.
  • Countries who are on or close to the equator don’t need to observe Daylight Saving Time because around the Earth’s circumference, the days and nights are always 12 hours long and there are no seasonal changes in the length of daylight hours or darkness. Way to go, Ecuador!
  • India has a single national time, which is UTC+05:30. And no, not all countries use whole hours for their UTC offset. Nepal even went as far as to use a time that is UTC+05:45.
  • Hawaii never changed its time from UTC-10:00 (it doesn’t observe DST). The fun fact is that Hawaii is in the same time zone as Alaska in the winter months.
  • The date of December 30, 2011 did not exist for Samoan residents. On that day, the country skipped a whole day when it moved time zones.

So there you have it: with time zones and the brief history of time explained, you’ll never mix your time zones up again or mistake EDT for a static time zone – remember, while not everyone may be happy about it, DST still affects the Eastern Daylight Time zone, so keep that in mind when reaching out to your friends in Florida or Vermont!

GMT – Greenwich Mean Time

Like most people, you’ve probably heard of GMT, or the Greenwhich Mean Time, and you know it’s used to refer to a time zone. However, you’ve probably also heard of UTC, and often, GMT and UTC are confused. Why? While both terms are used to define the “zero” hour on which the time zone calculations around the world are based, there is one big difference between GMT and UTC – and that is, one is a time zone and the other is a time standard. Curiously enough, the history of using GMT and UTC is intertwined, and it’s no wonder it’s still causing confusion. To clear it up, let’s talk about time zones, UTC, UTC offset, and the GMT time zone specifically: after all, time is precious, and understanding time zones can save you a lot of stress and hassle if you work or communicate with people around the world. And if you’re here for some fascinating time zone trivia, be sure to read the entire article – we’ve listed some fun time zone facts at the bottom of the page.

Ready to get your time right? Let’s dig right in:

What Are Time Zones Exactly?

You know that most countries around the world have their own time zone, but you’re not sure why? There’s a simple explanation: Earth rotates by 15 degrees every hour, and that means that noon hits different places of the planet at different times. Midday in Hawaii will occur at a different time than in Moscow precisely because of the rotation of the Earth, so to make sense of time around the world and to calculate what time is it where, time zones were introduced. This happened in the late nineteenth century when a Scottish-Canadian engineer and inventor Sandford Fleming proposed dividing the Earth into 24 slices of 15 degrees each. Each of these slices is a time zone, and each is coordinated using the Coordinated Universal Time (UTC) standard. The UTC standard monitors atomic time and is always at the “zero” hour; anything West of UTC will have a minus offset, and anything East of it will have a positive offset (that’s why you hear time being “behind” or “ahead” when you’re looking at different time zones around the world). As an example, Eastern Standard Time (New York Time) is UTC-5, meaning it’s five hours behind UTC, whereas time in Central Asia will be at UTC+5 – that is, five hours ahead. However, you’ve probably also noticed the same time zones referred to as GMT -5 or GMT+5, and it’s equally correct… or is it? If UTC is a time standard, and GMT is a time zone, why the confusion, and why is UTC and GMT used interchangeably? Let’s take a closer look at GMT to figure it out.

What Is Greenwich Mean Time?

Greenwich Mean Time, abbreviated GMT, is a time zone that covers parts of Europe, Africa and Antarctica. At the center of GMT is the Royal Observatory in Greenwich, London, which sits on the Greenwich Meridian, or longitude zero. For several centuries, GMT was used as both the time standard and a time zone, but it’s not the same as UTC: nowadays, GMT is firmly considered a time zone, and UTC is a time standard. In essence, GMT is basically UTC+0:00. In other words, Greenwich Mean Time has no UTC offset. 

However, this does not mean that all countries in the GMT time zone have the same hour. Some countries are observing Daylight Saving time, so they are in the GMT+1 time zone during the warm months of the year. In fact, even the United Kingdom is observing Daylight Saving Time during the summer months. In other words, the country that invented GMT is not in GMT time all year round. During summer, the UK is in the BST (British Standard Time) time zone.

It’s sometimes confusing to think that several countries around the world can share the time zone, but a simple way of understanding it is this: time zones are defined by degrees East or West rather than degrees South or North. That is, a time zone will cover the same countries vertically, which is why the UK and South Africa observe the same time. Once again, this has to do with the rotation of the Earth: noon is noon from North to South, because the poles do not move; West to East, however, sees a difference as the Earth turns around its own axis. Funnily enough, while time zones are technically strictly defined by geography, it can sometimes be a purely political decision. For example, India spans a vast territory with several time zones in the geographical sense, but ever since the colonial era, the country observes only one single time zone from border to border. It’s the same with China: although its territory is massive and easily hosts at least three or four time zones, the entire country observes only one – Beijing – time. It’s weird to think that the sun is only rising in Mumbai and is already at noon in Kolkata, but both cities agree it’s 9am as per India’s one time zone policy – but then, perhaps even time keeping can be an agreement rather than objective reality.

A Short History of GMT

After all, this is precisely what GMT is: an agreement. Introduced to help with naval navigation when travelling around the world, GMT was once the international civil time standard. GMT was established in the seventeenth century by the Royal Observatory in Greenwich, and it was used by sailors and naval officers as a time reference at different locations around the world. Sail fifteen degrees West of the Greenwich Meridian, and you offset the time by an hour; sail another fifteen degrees West, and it’s an offset by two hours, and so on.

However, we now know what the seventeenth century sailors did not: that GMT isn’t as precise as we once thought. Remember that whole Earth rotation thing? Well, as scientists have observed, there sometimes are slight irregularities in the rotation rate, and those irregularities sometimes cause what we know as “leap seconds”, or moments when zero hour isn’t exactly zero but is a few seconds off. To account for those missing seconds, the time standard needs to be periodically adjusted to follow the real, atomic time – and this is where UTC comes in.

UTC is a time standard that sets the base for time keeping and time zones around the world. However, in the United Kingdom, GMT is still being used for civil purposes, even though not formally. The Greenwich Mean Time was created in England and adopted at the International Meridian Conference of 1884; then, the Earth was split into 24 time zones, with each zone being based on the Greenwich Meridian Time. Each time zone had an offset of a number of hours ahead of GMT or behind GMT, as we’ve explained before.

However, because Earth’s rotation is irregular and slows down every year, GMT was replaced as the world’s standard by the Coordinated Universal Time standard. UTC time is kept using extremely precise atomic clocks that are placed in various locations around the world. UTC also has a leap second system in place. Because the Earth’s rotation is slowing down, there are minor differences between the UTC time and the atomic clock time. Periodically, a second is added to UTC to make up for the difference. Up to date, 27 additions have been made, so while GMT may sometimes be used to refer to a time standard, it would already be 27 seconds late – whereas UTC is not, thanks to those atomic clocks.

So can you still use GMT and UTC together? Sort of: whether you say UTC-5 or GMT-5, it’ll still define New York Time. For the sake of clarity, though, just remember that GMT now defines a time zone along the zero longitude, while UTC is a precise time standard based on atomic clocks.

How Does GMT Work?

The way Greenwich Mean Time (GMT) works is a little bit different from standard time zones such as EST or PST or daylight time zones such as CDT or EDT. In fact, it’s not really what people call typical time zones. The main difference is that Greenwich Mean Time doesn’t have an offset from Coordinated Universal Time (UTC). In fact, it’s used alongside standard time on some continents, including Europe, Africa, North America, and Antarctica. 

Unlike usual time zones, Greenwich Mean Time is calculated based on the sun. Specifically, it’s 12:00 noon at Greenwich when the sun is at its highest point. At noon, the sun is exactly above the Prime Meridian, the hypothetical line of 0° longitude that splits Earth into two equal parts. 

Greenwich Mean Time is the “mean” of the everyday time in the year when the Sun crosses the Prime Meridian at the Royal Observatory Greenwich. Therefore, GMT is more of a clock time and not an astronomical time that varies during the year. Instead, GMT is measured by a clock every day. The main purpose of Greenwich Mean Time is to standardize time regardless of the location. Consequently, GMT watches are widely used by travelers.

How to Convert GMT to Other Time Zones?

Since GMT is not a standard time that has an offset from UTC, converting it to other time zones can be a little bit more complicated. Mostly, people calculate time based on the Coordinated Universal Time (UTC) which is considered a worldwide standard. GMT is no longer used within the community of scientists but sometimes people still want to find out how GMT works and how to convert it to other time zones. 

If you know the principles of converting UTC to different time zones, then you can convert GMT as well very easily. The reason is very simple. There is no time difference between Coordinated Universal Time and Greenwich Mean Time. However, it doesn’t mean that they are exactly the same. In fact, GMT is a time zone while UTC is just standard. GMT is officially used in some European and African countries. But no country uses UTC as local time. Interestingly, neither GMT nor UTC change for Daylight Saving Time but some countries that observe GMT switch to different time zones during DST

In order to convert GMT to other time zones, use the following guide:

  • Greenwich Mean Time is 4 hours ahead of Eastern Time (ET).
  • Greenwich Mean Time is 5 hours ahead of Central Time (CT).
  • Greenwich Mean Time is 6 hours ahead of Mountain Time (MT).
  • Greenwich Mean Time is 7 hours ahead of Pacific Time (PT). 

So, in order to convert GMT to ET you need to subtract 4 hours; In order to convert GMT to CT you need to subtract 5 hours; In order to convert GMT to MT you need to subtract 6 hours, and in order to convert GMT to PT you need to subtract 7 hours.

Major Territories in GMT

Greenwich Mean Time is being used as the standard time the entire year (there is no Daylight Saving time adjustment) in the following countries:

  • Burkina Faso
  • Mauritania
  • Guinea-Bissau
  • Ivory Coast
  • Guinea
  • Sierra Leone
  • Liberia
  • Iceland
  • Mali
  • Gambia
  • Senegal
  • Ghana
  • Ascension
  • Togo
  • Saint Helena
  • Tristan da Cunha

There are also 5 countries that are in the GMT time zone, but that observe Daylight Saving time (GMT+1):

  • United Kingdom
  • Portugal
  • Western Sahara
  • Republic of Ireland
  • Morocco

Other territories that are in the GMT time zone include the Faroe Islands and the Canary Islands.

Largest Cities in Greenwich Mean Time

There are many major cities in the GMT time zone and in the GMT+1 times zone (Daylight Saving Time). Notable examples include London, Belfast, Cardiff, Dublin, Madrid, Lisbon, Edinburgh, Cork, Galway, Port, Aveiro, Reykjavik, and Danmarkshavn, so fi you’re calling a friend or a colleague in any of those cities, Google what the GMT is at the moment – otherwise, you’re risking interrupting them at an inconvenient time.

The exact number of people residing in the Greenwich Mean Time Zone is not known. However, it is estimated that there are fewer people in GMT than there are in the EST time zone in the United States (around 142 million people live in the EST time zone). A little-known fact is that Greenland is in the same time zone as Britain. Weird, right?

What is a GMT watch?

Did you know that GMT is the only time zone that has a special watch calculating GMT time? GMT watch is a 24-hour format watch that measures a second-time zone. Surprisingly, GMT watches aren’t made with the usual 24-hour scale but it’s accompanied by several benefits. 

GMT watches allow customers to set an additional time zone. Therefore, you can choose one, two, or three additional time zones on your watch. The watch has the ability to rotate once every 24 hours. It’s a perfect way to observe time together at various time zones without calculating time or using online time converters. 

Another benefit of GMT watches is that if you own one, there’s no way that you misinterpret a.m. with p.m. or vice versa. It’s an especially useful function for those who travel during the night. This function is caused by the fact that all 24 hours are accounted for on a watch and you just can’t confuse a.m. and p.m. As a result, GMT watches are frequently used by pilots as they ease the process of communication and navigation and help them avoid confusion. 

The First Public GMT Watch in the History

The Shepherd gate clock is considered as the first GMT watch ever that showed the public Greenwich Mean Time. The clock is connected to the Shepherd master clock and was installed at the Royal Observatory Greenwich in 1852. Since it’s masted from far away, the Shepherd gate clock is also called the “slave” clock. 

This network of “master” and “slave” clocks was created and installed by Charles Shepherd. Today it’s rather unusual in using the 24-hour dial but originally, it showed astronomical time starting at 12 noon instead of midnight. The most obvious thing about the Shepherd gate clock is that it has 24 hours instead of the usual 12 hours. Therefore, the 12 o’clock hour hand is pointing down rather than upwards. 

From 1850 to 1893, the Shepherd master clock led the time system of Great Britain. Using the telegraph wires, the clock sent the time to the major cities such as London, Edinburgh, Glasgow, Dublin, Belfast, and more. Even more, from 1866 time was also sent to Harvard University in Cambridge and Massachusetts. 

Back then, the Shepherd gate clock played the most important role in distributing accurate time to people in various places of the world. As a result, today it’s considered one of the most important clocks that were ever made. 

The first thing you notice about the clock is that it has 24 hours on its face rather than the usual 12. That means at 12 noon the hour hand is pointing straight down rather than straight up.

Initially, the Shepherd gate clock showed astronomical time according to which the counting of the 24 hours of a day starts at noon. However, in the 20th century. The clock was changed to GMT and from this time the counting of 24 hours started from midnight. The clock hasn’t been adapted to British Summer Time and today the clock still shows the GMT.

Interesting Facts About Time Zones

Now that you know everything there is to know about Greenwich Mean Time, UTC, and the UTC offset, let’s discover a few fascinating facts about time zones. Some of these are seriously mind-blowing:

  • Want to know what’s the time in space? It turns out, the time on the International Space Station follows Greenwich Mean Time. There is also an atomic clock placed on the space station to calculate the precise time for the UTC standard, but as a rule, astronauts adhere to the good old GMT.
  • GMT was the first standard to refer to the noon as zero hours. All other standards referred to midnight as zero hours (this practice is dating back to the Romans) – until the Brits intervened.
  • When GMT was established at the Royal Observatory in Greenwich, the site was declared to be “by international decree, the official starting point for every new day, year, and millennium.” No pressure, Greenwich!
  • The United Kingdom is not always on GMT because it observes Daylight Saving time during the summer. In other words, the British are on GMT+1 during the summer months, even though they created the GMT time standard… it seems the Brits are in the habit of getting ahead of themselves!
  • GMT is also called Western European time and sometimes Greenwich Mean UT (an abbreviation of Universal Time). It’s convenient but inaccurate as several Western European countries are in fact in GMT+1 or GMT+2, but then, it’s merely an hour’s difference.
  • Several countries such as Belgium and Canada use Greenwich Mean Time to define their local time. Hey, if it works, it works.
  • China is huge, yet it only has one single time zone: GMT+8:00, referred to internally as Beijing time. On the other hand, France, although small in comparison, has as many as 12 different time zones because it still holds territories around the world; bizarrely enough, this means that the sun never sets over France – we bet Louis XIV, or the Sun King, would be amused by this fact.
  • There is a three-hour time difference between China and Pakistan, and they share a border. If you were to travel between the two, you would need to adjust your clock by three hours as soon as you crossed the border, even if it took you five minutes to complete the actual crossing… Go figure!
  • Speaking of borders: the tiny island of Märket in the Baltic Sea is the size of three football fields, but it observes two different time zones because it belongs to both Sweden and Finland. Although you can literally walk to either side within a minute, you’ll need to adjust your watch to Swedish or Finnish time accordingly.
  • Russia spans over 12 time zones (yes, it’s huge). However, the Russians use just 9 time zones. Why? Because Vladimir Putin, the president, decided to get rid of 3 of the times zones. They are no longer being used in Russia – indefinitely. Even time has nothing on Mr. Putin, it would seem.
  • Not all countries use whole hours in their UTC offset. For example, India uses an offset of 5:30 hours (UTC+05:30). And Nepal time is UTC+05:45. So there are fractions of an hour being used for the UTC offset as well. Talk about attention to detail!
  • Feel like having multiple birthday parties? Thanks to the time zones, you can: celebrate your birthday at home, hop on a plane, and fly to a country that’s several time zones behind. Lo and behold: it’s your birthday again!
  • In fact, you can also fly into…yesterday or tomorrow. Because of the time zones across the world, you can leave Paris at 8am on Monday morning and find yourself back on Sunday in LA. Daylight savings suddenly start to seem cute, doesn’t it?

Now that you know what’s a time standard and what’s a time zone, what’s the history behind the Greenwich Mean Time, and how this whole world timekeeping works, you’ll never miscalculate time again – even in space. However, if you work or communicate with people scattered across the world, it’s usually more convenient to simply use a time zone converter rather than trying to calculate who’s behind and who’s ahead – after all, time is precious.

EST – Eastern Standard Time Zone

If you have ever traveled internationally, you’re probably familiar with the confusing effects of jetlag and the adaptation to a different time in another country. It’s weird to think that you can, quite literally, travel in time: if you’re leaving Paris or London and heading to Phoenix or San Francisco, you’ll arrive earlier than you’ve left. By contrast, if you’re flying to Tokyo or Vladivostok, you’re catching up with tomorrow, as Japan and Russia are eleven time zones ahead of Europe. Sounds crazy, right? However, time zones have been created for a wide variety of social, legal, and commercial reasons. Time zones were set to determine noon around the world; because of the Earth’s rotation, noon comes at different times in different places around the world. To keep track of time around the planet, countries adhere to certain time zones. Truth be told, it is very helpful for countries and people who do business together and who conduct all sorts of other activities together to keep the same time. Because of this fact, time zones usually follow the boundaries of countries or regions (although there are curious exceptions to this).

EST Eastern Standard Time Zone

So what are time zones, how are they set, and how is time calculated around the world?

To make things simple, all time zones are defined by the Coordinated Universal Time (UTC), which is a time standard. However, most people don’t know exactly what a time zone is, and they may not know what UTC is, either. In fact, most people erroneously believe they are in the UTC time zone when they are really in the GMT time zone. It gets even more confusing knowing that the North and the South Poles have no time zones at all, and astronauts follow the GMT regardless of where they are… So let’s start at the beginning and explain what time zones are, what UTC is, and what it is used for, and then analyze the EST time zone which covers several countries and major cities in the Americas. And if you’re after some fun time zone facts, make sure to read the entire page – we’ve listed some weird and wonderful time zone facts at the bottom of the post.

UTC and UTC Offset: What Are They?

UTC stands for Coordinated Universal Time. It is the standard when it comes to measuring time around the world; originating from the GMT, or the Greenwich Mean Time, which used to be the only time standard measured at the Greenwich Meridian (0 longitude), UTC now defines the „zero hour“ time standard and is commonly mistaken for GMT which is a time zone rather than a time standard. It may sound confusing, but think of it this way: while both stand for the exact time at the zero longitude, UTC is the standard, and GMT is the time zone.

All time zones around the world are UTC plus or minus some time (usually one or more hours). Anything that is West from the zero longitude will have a minus offset, and anything that is East will have a plus offset.

EST, the Eastern Standard Time observed in the Americas, as an example, is UTC-05:00, while the time observed in Central Asia will be UTC+05:00.

This difference from UTC time is the UTC offset. In the case of the Eastern Standard Time zone, the time is 5 hours behind UTC time. The offset is usually one or more whole hours, but there are countries with offsets of 30 minutes (India, for example) and even 45 minutes (Nepal, for example). 

And while there are many countries that are split between time zones (Russia spans over 12 of them), there are also countries that only observe one time zone despite spanning vast territories (China, for example). In other words, while most countries around the world observe time zones correlating to their geographical realities, sometimes time zone decisions can be purely political – or, in the case of France with numerous territories around the world, simply bizarre because of historical reasons.

Brief History of EST

Most western countries can’t imagine measuring the time without nowadays’ standards but did you know that EST was founded only several centuries ago?

For millions of years, people measured time by using natural resources such as the sun or moon. Both ancient people and those from the 18th century used to observe the sun every day in order to find out what time of the day it was. Consequently, the majority of people were well-aware of nature and its wonders. Specifically, when the sun was the highest in the sky, they could tell that it was noon. Obviously, they couldn’t calculate the exact time but it was enough to plan their day and make predictions about the following events. 

However, the need for the development of more exact mechanisms for calculating time was becoming more and more necessary. As a result, in the Middle Ages, there were already some advancements. In fact, in the Middle Ages people used to calculate the time based on Sundials. It’s a device that can tell the exact time according to the apparent position of the sun in the sky. Sundials looked pretty much like today’s watches and soon, mechanical clocks began to develop. It was the time when cities started setting their two clocks based on the sun position and as a result, each city had its own time, which was a bit different from others. The time of this period was called Apparent Solar Time.

That’s how ancient people used to find out the time during the day. While many people find these methods still very interesting in today’s advanced world, no one argues that the development of worldwide time zones was an important step in the history of mankind.

Speaking of history: worldwide time zones were introduced in 1878 by Sandford Fleming, a Scottish – Canadian engineer, and inventor. Following Fleming’s proposal, the world was divided into 24 time zones. In 1883, railroad companies in the US began using Fleming’s time zones and eventually defined the Pacific, Mountain, Central, and Eastern Time zones in 1895.

Introduction of EST in the United States

The United States was one of the first nations who adapted to Eastern Standard Time. The country started using a standard time system on November 18, 1883. By this time, the majority of the largest railway systems switched to standard time. The new system involved four time zones:  Eastern, Central, Mountain, and Pacific. The clocks were synchronized which made communication and the traveling process between various states easier. However, it was long before the railroad industry’s initiative would spread to the entire country. The new system of timezone still wasn’t official in the United States before creating the Standard Time Act in 1918.

The reason was that people couldn’t adapt to the changes so quickly and they continued using old times for years. But its benefits were becoming more and more obvious. Specifically, using EST was accompanied by plenty of advantages in the fields of travel and communication. In 1918 the country declared the official law with the Standard Time Act and the United States started adopting the time zones based on the recommendations of the railroads. The act also established daylight saving time. 

Standard Time was quickly spread across the ocean and reached westward in 1938 since the Interstate Commerce Commission (ICC) introduced new principles of time-zone management from railroads. The states rapidly adapted to the new time standards and implemented them using EST. For instance, Kentucky added its counties to the Eastern Standard Time in the 1940s, and the process finished in 1961 when the entire state switched to EST. 
Another important date for the introduction of EST in the United States is 1884 when the International Meridian Conference was held in Washington, D.C. It was the time when the delegates from various nations met and agreed upon choosing the Royal Observatory in Greenwich, England as the official prime meridian (“zero” point). According to their decision, traveling east from the prime meridian meant gaining an hour with each time zone, while traveling west meant moving backward by an hour. Today the great part of the United States and plenty of other countries accept Eastern Standard Time.

How Does EST Work Today?

The mechanism of Eastern Standard Time (EST) is pretty easy to understand, especially if you know the basic principles of time zones. As simple as that, there are 24 hours within a day and 360 degrees of longitude around the globe. If we divide this 360 degrees by 24 hours, we will get 15 degrees of longitude, equal to a one-hour difference between each time zone. Therefore, there are 24 time zones in total. Each of them is measured from a starting, “zero” point called the Greenwich Meridian because it’s located at England’s Greenwich Observatory. Time at this place is known as Greenwich Mean Time (GMT) or Universal Time. 


Eastern Standard Time (EST) is GMT minus 5 hours. Therefore, when it’s noon in the Eastern time zone, it will be 5 p.m. in Greenwich. Eastern Standard Time spans from northern Canada to South Panama which is near the Equator. EST shares the border with Atlantic Standard Time (AST) in the east, while it’s surrounded by Central Standard Time (CST) in the west.

What Are Eastern Standard Time (EST) and Eastern Daylight Time (EDT)?

EST (Or Eastern Standard Time Zone) is UTC-5:00. In other words, the Eastern Standard Time zone has a UTC offset of minus 5 hours. This means that all regions in the Eastern Standard Time Zone are 5 hours behind Coordinated Universal Time. When it is 12 PM in London (which is in UTC), it is just 7 PM in Connecticut and Ontario.

Eastern Daylight Time (EDT) is just 4 hours behind Coordinated Universal Time (UTC-4:00) because it takes into account daylight saving time. Daylight saving time is observed during spring and summer. The states in the EST time zone move to the EDT time zone on the second Sunday of March. They transition back to EST on the first Sunday of November. This transition is aimed to add one hour of daylight during the warm seasons; a popular myth is that in the US, the Daylight Savings was introduced to help farmers grow more food, but in fact, the move was instead lobbied by urban dwellers and corporations hoping to extend working hours.

Territories in the Eastern Standard Time Zone

The Eastern Standard Time zone covers the eastern part of the United States, some parts of Canada, and a single state in Mexico: Quintana Roo. In addition, EST time is being used in Panama, part of the Amazon region (Brazil), Colombia,  Ecuador, and the Caribbean Islands including Cuba. It may be funny to think the time is the same in Quito, Havana, New York, and Bogota, but this is because these major capitals are aligned vertically, which means that geographically, they all sit in the same time zone. 

There are a total of 17 states that are entirely in the EST time zone in the United States. However, be aware that some of these states observe Daylight Saving Time, so they will transition to the EDT time zone during the summer months. They will return to EST time on the second Sunday of March, at 2 AM, however. Here are the states that are encompassed by the EST zone in the US:

  • Maryland
  • Georgia
  • New York
  • Maine
  • West Virginia
  • New Hampshire
  • Connecticut
  • Delaware
  • New Jersey
  • South Carolina
  • North Carolina
  • Ohio
  • Pennsylvania
  • Rhode Island
  • Vermont
  • Massachusetts
  • Virginia

Additionally, in the United States, there are 5 states that are split between the Eastern Time Zone and Central Standard Time (CST): Indiana, Tennessee, Florida, Kentucky, and Michigan. Interestingly, the time zone definitions in the US were initiated by railroad companies, but when the Interstate Commerce Commission took over time zone management in 1938, the boundaries of the Eastern Time Zone have moved West. Once again, commercial and social factors conquered geography.

In Canada, there are just three territories that are partly in the EST time zone: Quebec, Ontario, and Nunavut. It is also important to note that these provinces observe Daylight Saving Time in sync with the US, even though there are some very minor exceptions.

The EST Time Zone Major Cities in EST Time Zone

Because the EST time zone covers so much of the United States, there are dozens of major cities in the EST time zone in the US. In fact, most people think about the United States when they hear EST time. And they are not wrong to do so: notable examples of large cities in the US include New York City, Washington D.C., Philadelphia, Florida, New Jersey, Atlanta, Baltimore, Buffalo, and Cleveland. Other major cities in the EST time zone are Ontario, Quebec, Guayaquil, Hamilton, Bogota, Nassau, Lima, Panama City, Quito, and Havana. However, although the EST time zone covers the majority of the US, keep in mind that „New York time“ isn’t the same as time in LA or San Francisco, so if you’re calling a friend or a work contact on the West Coast, be sure to calculate what time it is there rather than rely on New York and EST.

It is estimated that almost 142 million people reside in the Eastern Standard Time Zone of the United States. New York (over 19 million people), Florida (almost 17 million people), and Pennsylvania (around 12.5 million people) contribute the most to the total number of residents. However, even though this number seems pretty large, it is not. China, for example, is entirely in one time zone despite having almost 1.38 billion people (as of 2016). How is this possible? The Chinese government had decided the entire country should follow Beijing time – convenient or not.

How to Convert EST to Other Time Zones?

Converting the EST time to other time zones is probably the easiest by using various online tools. Millions of people traveling around the world try to find out the exact time of their destinations before they arrive. However, you won’t have to spend any more time if you understand the basic principles of converting EST to other time zones. Just remember that

  • EST is 1 hour ahead of Central Standard Time (CST). 
  • EST is 2 hours ahead of Mountain Standard Time (MST).
  • EST is 3 hours ahead of Pacific Standard Time (PST).

Therefore, to convert EST to CST, you should discount one hour; to convert EST to MST you should discount two hours, and to convert EST to PST, you should discount three hours.

Little-Known Facts About Time Zones

Without time zones, it would be impossible for the Sun to be at its highest point in the sky at noon in all countries on Earth. The Earth rotates 15 degrees per hour, so it makes sense to divide the world into 24 time zones, with each one of them being 15 degrees in size. Now that you know what time zones are and how they are used, and also know what UTC and the UTC offset are, let’s take a look at some interesting things when it comes to time zones:

  • The continental United States has four different time zones: Mountain Time ZoneCentral Time Zone, Eastern Time Zone, and Pacific Time Zone.
  • UTC, also known as Greenwich Mean Time, is centered on the Greenwich Observatory in England. The point is, obviously, called the Greenwich Meridian.
  • The EST time zone is the de facto official time for the entire United States because it is the time zone of the capital city, which is Washington D.C.
  • Over half of the United States population is in the Eastern Time zone and EST also includes the most populous city in the US, New York City.
  • TV Schedules in the US are most of the time posted in Eastern Time, and so are most newspapers. Programs are broadcasted at different hours across the United States to take into account the different time zones. Live events, however, are scheduled in Eastern Time and Pacific Time. Viewers must calculate the starting hour on their own if they are in a different time zone.
  • Canada uses the same number of time zones as the United States: 6. However, France has by far the most time zones because it has a number of territories around the world. There are 12 time zones in France in total; in essence this means that the sun never sets in France – a bizarre thought, but true nonetheless.
  • All computers and mobile phones will automatically adjust their clock when they get to a different time zone. However, your wristwatch will not; you need to adjust it manually.
  • Russia is geographically located in as many as twelve time zones. However, in 2010, president Vladimir Putin decided to erase 3 of the time zones, so now Russia only has 9 times zones. The decision was taken to aid commerce and communications between some of the vast regions of Russia and Moscow – but how do the inhabitants of Siberia feel about it remains unknown.
  • Taking a plane to a region that has a negative UTC offset is like going back in time. You may leave at 8 PM and arrive in the other country at 4 PM. Equally, if you head East, you travel into the future. This happens because of time zone differences and is the cause for jet lag. Curiously enough, jetlag is easier to battle when you travel West. It turns out, traveling East extends the day, and our bodies struggle with this change much more than having the day shortened, which is what happens when you travel West.
  • Neither the North or the South Poles have time zones – because all of the longtitude lines meet at the poles, there are no official time zones allocated to the South or the North Pole. Does that mean that the time stands still at the Earth’s Poles? Not quite – most international research centers simply follow the time zone of the nearest inhabited area or their own home country. 
  • Wonder what time is it in space? Turns out, astronauts on the International Space Station follow the GMT time zone.
  • North Korea is the only country in the world that has invented its own time zone. It only last a few years, but between 2015 and 2018, North Korea had declared it observes its own Pyongyang Time. It has moved back to observing the same time as South Korea and Japan since, but kudos for trying to save their own time!
  • The only two states in the US that do not switch to daylight saving time are Hawaii and Arizona. In addition, US territories like Guam and Puerto Rico also skip the transition.
  • Iran, Sri Lanka and Afghanistan are among the few countries in the world that split time zones by half-hour: Iran is GMT+03:30, for example. Even more mind-boggling are some places in New Zealand and Western Australia, splitting time zone differences into fifteen-minute intervals.
  • The tiniest place on Earth split between two time zones is the island of Märket in the Baltic Sea. The island belongs to both Sweden and Finland and, as a result, observes the Swedish and the Finnish time with the difference of one hour. It would perhaps make sense for a larger island, but Märket is the size of four football fields. 

Bottom Line

Now as you’re well informed about the Eastern Standard time and its history, understand its mechanism and know the territories that use EST, you can easily call yourself an expert in the field of EST time zones because that’s pretty much everything an average person needs to know about Eastern Standard Time. We hope that you’ll no longer have problems converting your time to other time zones but still, there’s no way that you can avoid jet lag and its accompanying confusing feelings. Just get used to the fact and travel safely!

UTC Time – Coordinated Universal Time

When it comes to understanding world time, most people don’t know what UTC is and what the UTC time. Curiously, UTC is both a time standard and a time zone, and it’s frequently used to describe either… Confused yet? To shed light on the matter, let’s talk about what time zones really are, what UTC is, and what are some of the major countries and cities in UTC. 

Understanding time zones and the UTC time standard is essential if you’re traveling if you work with people in different countries, or simply for social reasons. For example, if you’re based in London, UK, and you’re calling someone in Los Angeles, US, keep in mind they’re eight hours behind you. This means that if you’re trying to reach them at 10 AM your time, you’re calling them at 2 in the morning in LA! Needless to say, your Los Angeles friend won’t be happy to answer that call.

In addition to time zone confusion, UTC is often used instead of GMT, the Greenwich Mean Time. To find out why and to learn some fun time zone facts to outshine your trivia night rivals, let’s dig into the history, use, and curious facts about the UTC and time zones in general.

What Is a Time Zone?

A time zone is a region on Earth that observes the same time. This way, it will be the same hour in all the countries and the cities in the particular time zone they observe. Time zones run horizontally rather than vertically: Moscow and Paris will have different time zones, but Cape Town and Madrid observe the same time. This is because time zones aren’t about longitude but rather, latitude due to the rotation of the Earth. 

As you can imagine, noon is at different times in each country, which means that noon (12 PM) would be observed at different times from country to country corresponding to their position West or East. Without a standard time that all countries in a time zone must observe, the countries would never observe at the same time. 

Imagine the chaos this would cause: without agreeing on standard time, we wouldn’t be able to agree on, well, anything else. Time zones are very important for commercial and social activities, legal reasons, military use, trade, and just about every other human activity on the planet. 

As long as two countries are in the same time zone, you won’t have any communication issues. If the person you are speaking to or who ships your product is in a different time zone, it may be midnight your time when it’s noon his or her time. You can imagine the trouble you would have communicating with people who are 6 to 12 hours ahead or behind your time! This is where time zones come in: you can plan your communication by calculating the time differences between you and the person you’re trying to reach, and suggest a time that suits you both.

In addition, time zones are very important for military purposes. The military uses different names for the different time zones, but the way they work is exactly the same. For example, UTC is Zulu Time in military jargon.

Finally, time zones matter when it comes to legal issues and work contracts. If you live in Seattle and you’ve promised to deliver a certain project to an Ireland-based company by, say, Monday morning, you better get it done on Sunday evening your time – Seattle is eight hours behind Dublin, which means your today is their tomorrow and, unless agreed otherwise, they will be expecting results on their time – not yours.

What Is UTC?

UTC stands for Coordinated Universal Time. This is the primary time standard in the world, and the standard after which the entire world regulates its time. Your clock is regulated by the Coordinated Universal Time standard. 

UTC is not a time zone, even though people use it as one. Again, UTC is a time standard. UTC has a difference of less than one second of mean solar time at a longitude of 0 degrees. In other words, UTC is, in essence, the „zero hour“ time. 

Even though this time standard came to use from the start of 1960, it was officially adopted a little later, in 1967. Of course, the time standard has undergone several adjustments over time, and the UTC we use today was implemented in 1972.

It contains what is called “leap seconds,” which makes it easy to adjust the time in the future if need be. Why adjust the UTC in the first place? This is because of irregularities in the Earth’s rotation rate. Because of this irregular rotation rate, UTC is slowly drifting away from the extremely precise atomic time. As such, it needs to be adjusted periodically. 

Depending on where you live, your country probably observes Daylight Saving Time (DST) moving one hour back or forth in the spring and the fall. UTC, however, is not affected by this and it will never change for DST. Essentially, UTC is the one unmovable time standard that will not change under any circumstances, except the minor lea second adjustments to account for precise atomic time.

Brief History of UTC

The history of UTC dates back to 1884 when the International Meridian Conference was held in Washington D.C. It was indeed one of the most important events in the history of the timezone adaptation. In fact, that’s when the 24-hour time zone system was first introduced. The representatives of the countries who attended the conference decided to choose a particular time for global use. By this time, having different time systems was a severe problem for worldwide travel, communication, economy, and politics. Therefore, establishing a global timezone system seemed like a rational step for everybody. 

The representatives of different countries determined the Royal Observatory in Greenwich, London as the starting point of calculating the time and called it the Prime Meridian. Many cities quickly followed the change and switched to one of the five one-hour wide time zones across the continent. 1884 was the exact time when the Universal Time or UT started functioning as well.

Nowadays people often confuse UTC and GMT with each other and use these two terms interchangeably. While at a first glance they are pretty much alike, actually, these two terms are not completely the same. They are technically the same but they describe the different time-related features. We’ll describe the difference below and keep on focusing on the history of the Universal Time for now. 

Although Greenwich meridian was selected as the Prime Meridian, from the 1950s the world switched to using GMT as the new time standard. However, soon it became obvious that there were more effective ways for measuring the time. With the invention of atomic clocks in the 20th century, using solar time for calculating the time wasn’t satisfying anymore. As a result, at the beginning of 1960, the world started using the new standard for coordinated time. 

Coordinated Universal Time (UTC) was first introduced on January 1, 1960. However, it became an official term only in 1967 by the International Radio Consultative Committee and replaced GMT a year later. On January 1, 1972, UTC was adjusted by adding “leap seconds” – one-second adjustment for accommodating the difference between precise time and observed solar time. Today’s UTC is in line with the Earth’s rotation. Still, it’s not entirely even but it’s the most optimal way to calculate the time up to now. 

UTC and Greenwich Mean Time: The Differences

Many people say that they live in the UTC time zone. While it may make sense in casual day to day use, this is, in fact, an incorrect statement. Why? Because UTC is a time standard rather than a time zone. 

What they should be saying instead is that they live in the GMT time zone. GMT, an abbreviation for Greenwich Time Zone, is the time zone that observes UTC+00:00 time (exact UTC time). GMT was established in 1675 by the Royal Observatory in Greenwich, UK, to define the mean solar time in this precise location. This was done to help British sailors figure out the longitude from the Greenwich meridian (zero degrees) while at sea, giving them a standard reference time. In 1884, it was adopted as a standard at the International Meridian Conference, and it gave base to time zones as we know them today. From maritime use, the GMT was next adopted by the British railway system, then Ireland, and eventually, the entire world. However, GMT is not as precise as the UTC, and that’s why it has been replaced by the UTC standard. GMT is now firmly a time zone, whereas the UTC stands for the universal standard.

So how does it work today?

The plus sign in the +00:00 UTC is known as the offset from Coordinated Universal Time. It tells people by how many hours their time is offset from UTC. For example, the United States is in several time zones: Colorado is in UTC-07:00, while California, Nevada and Oregon are in UTC-08:00. Samoa, in contrast, has a time offset of UTC+13:00; Baker Island and Howland Island, on the other hand, have a negative offset of UTC-12:00. 

Once again, time zones aren’t about geographical locations based on their position of North vs South or international country boundaries but rather, the West-East coordination: the same country can have several different time zones, but one time zone may apply to several different countries. To make this easier, think of it this way: if you can draw a vertical line across the map, the countries on that line will share the same time zone. However, if you draw a horizontal line from West to East, the countries on the line will be in different time zones.

The differences in time between various countries on Earth can be huge, and some countries like Russia have as many as eleven time zones within their territory. On the other hand, some countries, despite their gargantuan size and millions of inhabitants, refuse to observe different time zones: India, as an example, observes just one time zone, the GMT +5:30. Although different regions in India had kept different time zones before, their time zones were unified during the colonial era to better manage the railway system. For better or worse, the unified time zone stuck, and Indians now observe the same time whether they live in Kmombai or Kolkata. Another example is China: although its immensely vast territory spans at least five geographical time zones, China only observes the UTC+08:00 time zone, or the Beijing time. It’s a little like trying to keep the same time regardless of whether you’re in Arizona or New York, but, surprisingly enough, the Chinese seem to manage just fine.

In addition to these oddities,  keep in mind that the GMT time zone, much like the UTC time standard, will never change for DST (Daylight Saving Time). However, some countries that observe DST will switch to a different time zone for this purpose. For example, the United Kingdom (who established GMT) switches to BST (or British Summer Time) during the summer months. As you might have guessed, BST time is 1 hour ahead of GMT time.

On the other hand, plenty of countries around the world do not bother to switch back and forth to the DST. Several South American countries such as Argentina and Peru as well as Asian countries like Thailand, Japan, and China, and most African countries do not change to DST and keep their time still – pun intended. Equally, some regions of the same country may or may not observe DST – for example, South Australia is on board with the DST changes, while Western Australia and Queensland are not.

How to Convert UTC to Other Time Zones?

Converting Coordinated Universal Time to other time zones and adjusting it to your local time is nothing difficult. For this, you just need to understand the basic principles of time conversion. But don’t worry if you find them too complicated because today there are many simple online tools in order to help people convert UTC to various time zones. 

First of all, you should understand that the world is divided into 24 time zones. However, this number is not 100% correct because some states and regions usually shift their times by half an hour from the 24-hour divisions. Still, Standard time is generally a whole number of hours from the UTC. The worldwide standard time is based on the work of atomic clocks that are kept at various laboratories around the world to maintain the time. 

Use the following guideline in order to convert UTC in different time zones:

  • Coordinated Universal Time (UTC) is 4 hours ahead of Eastern Time (EST)
  • Coordinated Universal Time (UTC) is 6 hours ahead of Central Standard Time (CST).
  • Coordinated Universal Time (UTC) is 6 hours ahead of Mountain Standard Time (MST).
  • Coordinated Universal Time (UTC) is 7 hours ahead of Pacific Time (PST).

Major Countries in the GMT Time Zone (Using Coordinated Universal Time)

Many countries in Europe and Africa have an offset of UTC+00:00. This means that they are in the GMT time zone. Here are the countries that use standard time all year round:

  • Burkina Faso in Africa
  • The Gambia in Africa
  • Mauritania in Africa
  • Ghana in Africa
  • Côte d’Ivoire in Africa
  • Guinea in Africa
  • Liberia in Africa
  • Mali in Africa
  • Senegal in Africa
  • Guinea-Bissau in Africa
  • Sierra Leone in Africa
  • Togo in Africa

There are also some Atlantic Islands:

  • Greenland
  • Iceland
  • Saint Helena
  • Ascension Island
  • Tristan da Cunha

In Europe, the following territories are in the GMT time zone, but only in the Northern Hemisphere winter period:

  • Alderney
  • United Kingdom
  • Guernsey
  • Sark
  • Faroe Islands
  • Herm
  • Isle of Man
  • Jersey
  • Ireland
  • Portugal (remember that the Azores area has an offset of UTC−01:00)

Although there are no official figures, the number of people who live in the GMT time zone is in the hundreds of millions. 

Important Cities in UTC

As you can imagine, there are a lot of major cities in the GMT time zone (observing UTC time). However, keep in mind that many of these cities are not observing UTC time all year round because of Daylight Saving Time and other time zone adjustments. Here are the major cities that observe UTC at one time or another during the year:

Problems with UTC

Even though UTC is a worldwide standard, it’s not an entirely ideal time system. In fact, Coordinated Universal Time is accompanied by some problems such as leap seconds or other issues. Therefore, it offers useful information which can be rather limited sometimes. Let’s dive deeper into the problems of UTC.

Leap Seconds

“Leap Seconds” is one of the biggest problems with the global use of UTC. As we already mentioned, it’s a one-second adjustment that is applied to the Coordinated Universal Time from time to time. The purpose of these seconds is to adjust the difference between the time measured by “atomic clocks” and observed solar time known as UT1. 

Usually, the Earth doesn’t move absolutely regularly and UT1 varies due to the changes in the Earth’s movements. Leap seconds are important for UTC to get ahead of observable solar time. This means that 0.9 is the maximum difference between the UTC and the solar time. This measurement is done by the International Earth Rotation and Reference Systems Service (IERS)  but it’s not entirely accurate which is why it’s considered a problem with UTC.

  • Observing daylight saving time (DST) in the cases of some countries is another problem related to UTC. While some countries stopped using daylight saving time, you still need to know the exact location with others in order to find out the accurate time. The reason is that some regions like Navajo Nation, in northeastern Arizona, still use DST. 
  • The date is interpreted differently by various calendars. Specifically, in the 16th century the world began using the Gregorian calendar which is used up to now but before, people used the Julian calendar for determining time and date. Therefore, sometimes interpreting the date universally can be problematic. 
  • Different countries started using UTC at different times. Therefore, if you want to determine the time in the past, you’re highly likely to encounter some issues.

Use of UTC

After all this discussion about the UTC, now it’s finally to state who actually uses Coordinated Universal Time. Surprisingly, people don’t directly use UTC. Generally, most people live in locations where time is calculated based on GMT and not UTC. But then, why do we need UTC after all?

The answer is very simple. UTC is the term mainly adjusted for the World Wide Web standards. The Network Time Protocol (NTP) is a system for clock synchronization between computer systems that has operated since 1985. The Protocol, which is now the oldest Internet protocol still used, uses information from the UTC system for transmitting the time. 

Besides, UTC is the time standard in aviation. Usually, maps, weather forecasts, flight plans, or air traffic control are based on the UTC. It’s important to avoid confusion about various time zones when airplanes move from one time zone to another.

Interesting Time Zone Facts

Even though UTC is a time standard and GMT is a time zone, UTC is often being used even by official sources. It is expected, in fact, that UTC will replace GMT in the near future. So, all things considered, it’s not a big mistake to say that you are in a UTC time zone – as long as you keep the right time!

Now that you know what Coordinated Universal Time is and where it applies, let’s take a look at some interesting time zone facts:

  • Most time zones are offset from UTC using whole hours. However, there are countries that have offsets that contain parts of an hour. For example, India is in UTC+05:30. Also, the Nepal Standard Time is basically UTC+05:45. Talk about attention to details!
  • There are proposals to replace the UTC with another standard – one that does not use leap seconds to adjust the time after the atomic clock time. 
  • The first leap second was added on June 30, 1972. In total, there have been 27 seconds added to UTC over the years, up to date.
  • The length of the mean solar day is increasing because the Earth’s rotational speed is slowly decreasing because of the tidal deceleration effect. Time to slow down, folks.
  • The Earth will keep slowing down its rotation, so more and more leap seconds will be added in the future to compensate.
  • Daylight saving time was created to help people enjoy more active hours during daylight… but most people still report feeling somewhat groggy and confused on the first few days after the DST change!
  • The differences in time zone have an interesting effect. While it may be Monday where you live, it may be Tuesday or even Sunday where the person you are talking to lives. In other words, your today is somebody’s tomorrow, and someone’s yesterday may be your now. 
  • It’s easy to forget about time zones when travelling by plane over long distances. Be careful not to call somebody at 3 in the morning thinking it’s 10 AM there as well!
  • Both cell phones and computers adjust time automatically when you travel from one time zone to another. But you will have to manually adjust your watch.
  • Did you know that you can have two birthdays? Just take a plane to another time zone and you can turn your clock back by anywhere from 3 to 12 hours.

So there you have it: UTC and time zones may be confusing at first, but once you figure out how standard time works, it’s just a matter of calculating the differences between the hours ahead or behind. And if you don’t have the time to check the hours, just use this simple time zone converter to check time in different countries around the world.

CDT – Central Daylight Time

Understanding the time standard and time zones is useful if you work, communicate, or collaborate with people who live in different countries than you. Knowing how time zones work and how to calculate time in different locations around the planet helps you plan and communicate better – after all, no one wants to get a work call or a Zoom invitation for midnight or two in the morning, even though it may be a perfectly reasonable time on your end! 

To clear up the confusion about time zones, explain CDT (Central Daylight Time), one of the major time zones in the world, we’ll dig into the science and history behind time zones and talk about how it works. Next up, we will provide a list of the major territories that are located in the CDT time zone, as well as all the major cities in this region. And to make time zones more fun, we’ll list some curious time zone facts and trivia at the end of the article, so be sure to read it till the end.

Ready to start keeping world time? Let’s dive right in:

What Is a Time Zone?

To start at the beginning, let’s explain what a time zone really is. Because the Earth is a sphere that rotates, it cannot be noon at the same time all over the world: as the Earth turns, the sun hits different regions at different times. When it’s evening in London or Frankfurt, the sun is only rising in Lima or Los Angeles; in other words, different regions of the world observe noon at a different time, and when it’s night in one region, it may be noon in another. 

To keep track of time around the world accurately, scientists split the planet into 24 slices, each slice accounting for 15 degrees of longitude counting from the Greenwich Meridian, also known as longitude zero. Each slice is a time zone that is 15, 30, 45, and so on degrees West or East from Greenwich; one slice accounts for one hour behind or ahead the Greenwich Mean Time (GMT), which sits atop the zero longitude. This way, it’s 12PM at noon everywhere in the same time zone.

Now, time zones are calculated by degrees West or East rather than North or South. This is because, once again, the Earth rotates around its axis, but the poles do not move. What this means is that it’s noon everywhere along the same longitude: it’s the same time in Madrid and Cape Town, despite these cities being thousands of miles away from each other. However, if the countries are located West or East of each other, they will observe a different time – this is why Spain and Russia, as an example, are in different time zones despite being much closer than Spain is to South Africa.

This may sound confusing at first, but keeping time this way offers a lot of benefits to people, companies, and even the military around the globe. As long as you know which time zone you are in and the UTC offset of another country, you can easily calculate the time in that country. To make it even clearer, let’s talk about UTC and the UTC offset for a bit.

What Is CDT Time?

Central Daylight Time (CDT) is a Daylight Saving Time zone that is also known as CDST (short for Central Daylight Saving Time) or NACDT (short for North American Central Daylight Time). And, as you’ve probably guessed it already, the CDT time zone covers large parts of the United States and North America. As was stated earlier, CDT is UTC-05:00. In other words, it has an UTC offset of 5 hours (CDT is 5 hours behind UTC). And because it is a Daylight Saving Time, CDT is only used during the summer months. In the winter, many of the territories covered by CDT switch to the CST (Central Standard Time) time zone.

Why do some countries around the world switch to Daylight Savings time, while others do not? In essence, moving the clocks forward and back in the spring and fall months is done to extend the daylight hours. During summer, the sun rises and sets later, which is why moving the time forward by one hour helps extend the daylight giving people more daylight hours and saving energy. In the fall, the sun begins to rise and set earlier, and that’s when clocks are moved one hour back to account for the difference.

However, not all countries around the world use daylight savings. This largely depends on their proximity to the equator: on the equator, the day always has 12 light hours and 12 dark hours, so for countries like Ecuador, there’s simply no need to move the clocks. In the Northern and Southern Hemisphere, however, the difference between the length of day in summer and winter is more pronounced, which is why most countries further away from the equator observe Daylight Savings time seasonally. Curiously, some countries haven’t quite agreed on observing Daylight Savings: in Australia, for example, some states switch to summer time while others do not, no doubt creating some confusion.

Although in the West, the daylight savings tradition is only about a hundred years old – the DST changes were first introduced in Germany and Canada at the beginning of the 20th century – the practice in itself isn’t new. Ancient Romans seem to have made use of daylight savings, too: history shows Romans used water clocks with different scales to adjust for different solar time throughout a year. 

Brief History of CDT

Unlike other time zones such as UTC or EST that have a long history, it hasn’t been so long since the world was introduced to the concept of Central Daylight Time (CDT). The reason is that CDT is not a usual time zone. Instead, as we already mentioned, CDT is used only in certain months and only in the Americas. Therefore, it’s more like an additional time zone than the major one. 

This alternative time zone originates in 2007 and is exclusively used in North America and some parts of Canada. However, there are still many areas in both countries that refuse to use CDT for stabilizing time during the summer.

For example, in Canada, the Western province of Saskatchewan doesn’t accept the seasonal change. The reason is that the province is closer to the Mountain Time Zone’s meridian geographically and they don’t need to switch to a different time zone to adjust the time. Instead, they decided to be a part of the Central Time Zone and chose a permanent daylight saving system, consequently. However, the city of Lloydminster refuses the idea of Central Time and uses Mountain Time with DST.

Moreover, Mexico also refused to adapt to the change. However, in December 2009, the Mexican Congress changed its opinion and let ten cities that are located at the borders switch to the CDT time schedule in 2010 according to the US standards. 
But these are just some of the many exceptions that we’ll review below. The first time when North America started using Central Daylight Time was in 2007 when the local time changed from 2:00 local standard time to 3:00 local daylight time. Since this time, it usually happens on the second Sunday in March and returns back to the standard time on the first Sunday of November.

How Does CDT Work?

Even when people understand the importance of using CDT, sometimes it’s hard to adapt to its mechanism and find out how the CDT actually works. The only obvious thing is that sometime in the spring we change our clocks so that we will save daylight time in the summer. But when exactly do people switch their clocks from 2 p.m. to 3 p.m?

In fact, most of the United States starts switching to central daylight time at 2 a.m. on the second Sunday in March. They return their clocks back to standard time on the first Sunday in November. Since different American states use different time zones, needless to say, that each time zone switches at a different time in the U.S. 

Accordingly, in the European Union, countries that accept the idea of CDT switch to the central daylight time on the last Sunday in March and return to the Universal Time (or the Greenwich Mean Time) on the last Sunday in October. Unlike the Americas, in the EU all the time zones change at the same time. 

CDT vs CST – Differences

First of all, CTD stands for Central Daylight Time while CST is Central Standard Time. CDT is exclusively a North American time zone that is used during Daylight Saving Time (DST) only from the second Sunday in March to the first Sunday in November. Unlike CTD, CST is used throughout all the remaining days except the days when CTD is used. 
The main reason why people often get confused about these two time zones is that they both refer to the central time zone. But they are not the same because they are used during different periods of the year. The main difference is that CDT is applied during daylight saving time and consequently, these two time zones differ with an offset of one hour. Other than this, CDT is exactly the same as CST. Both time zones exist at the same time and are a part of the standard time. However, they replace each other during some period of the year.

How to Convert CDT to Other Time Zones?

In order to convert CDT to other time zones, you should pay attention to the following details:

  • CDT is 5 hours behind the GMT (Greenwich Mean Time) and is used in North America.
  • CDT started at 2 a.m. on Sunday, 13 March in 2021.
  • CDT will end at 2 a.m. on Sunday, 7 November in 2021 and the clocks will be set one hour back. 

Now let’s see what CDT looks like in relation to other time zones.

  • CDT is 1 hour behind EDT (Eastern Daylight Time).
  • CDT is 1 hour ahead of MDT (Mountain Daylight Time).
  • CDT is 2 hours ahead of PDT (Pacific Daylight Time).

Consequently, in order to convert CDT to EDT you need to add one hour; To convert CDT to MDT you need to subtract one hour, and to convert CDT to PDT, you need to subtract two hours. 

Major Territories in CDT Time

There are many territories in the United States, Canada and Mexico that are encompassed by the CDT time zone. However, remember that most of these territories will switch to Central Standard Time during the winter months, as CDT is a Daylight Saving Time.

Here are the states in the United States what use CDT during summer and CST during winter:

  • Alabama
  • Arkansas
  • North-western part of Florida
  • Illinois
  • Indiana
  • Iowa
  • Kansas except some of its western counties
  • The Western part of Kentucky
  • Louisiana
  • The western part of Michigan
  • Minnesota
  • Mississippi
  • Missouri
  • Only the eastern parts of Nebraska
  • Only the northern and eastern counties of North Dakota
  • Oklahoma
  • Only the eastern parts of South Dakota
  • Only the western parts of Tennessee
  • Most of Texas
  • Wisconsin

In Canada, however, just 3 territories are mostly in the CDT time zone: most of Ontario, Manitoba and parts of Saskatchewan. There are also a lot of Mexican states that are in the CDT time zone during the summer:

  • Aguascalientes
  • Campeche
  • Chiapas
  • Coahuila
  • Colima
  • Distrito Federal
  • Durango
  • Guanajuato
  • Guerro
  • Hidalgo
  • Jalisco
  • León
  • Michoacán
  • Morelos
  • México
  • Nuevo León
  • Oaxaca
  • Puebla
  • Querétaro
  • Quintana Roo
  • San Luis Potosí
  • Tabasco
  • Tamaulipas
  • Tlaxcala
  • Veracruz
  • Yucatán
  • Zacatecas

Some other territories that are in the CDT time zone are: Belize, Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua. It is not officially known how many people live in the CDT time zone, but the estimates put this number at over 300 million, most of them in the United States. So whenever you’re trying to contact someone who lives in an area covered by the CDT time zone, it’s not just the time zone differences you need to calculate – depending on whether it’s summer or winter, there will be one hour difference.

Major Cities in CDT Time

Because it covers large parts of North America and Canada, there are many large metropolitan areas in the CDT time zone. Here are the most important of them:

  • Amarillo, Texas
  • Antigua, Guatemala
  • Austin, Texas
  • Baton Rouge, Louisiana
  • Birmingham, Alabama
  • Bloomington, Illinois
  • Cedar Rapids, Iowa
  • Chicago, Illinois
  • Dallas-Fort Worth, Texas
  • Des Moines, Iowa
  • Fargo, North Dakota
  • Grand Rapids, Manitoba
  • Guadalajara
  • Guatemala City, Guatemala
  • Houston, Texas
  • Iowa City, Iowa
  • Jackson, Mississippi
  • Kansas City, Missouri-Kansas
  • Lawrence, Kansas
  • Managua, Nicaragua
  • Memphis, Tennessee
  • Mérida, Yucatán
  • Mexico City
  • Milwaukee, Wisconsin
  • Monterrey, Nuevo León
  • New Orleans
  • Oklahoma City, Oklahoma
  • Panama City, Florida
  • Puebla City
  • Racine, Wisconsin
  • Regina, Saskatchewan
  • Sioux Falls, South Dakota
  • St. Louis, Missouri
  • San José, Costa Rica
  • San Luis Potosí City
  • San Pedro Sula, Honduras
  • San Salvador, El Salvador
  • Saskatoon, Saskatchewan
  • Springfield, Illinois
  • Tampico, Tamaulipas
  • Thompson, Manitoba
  • Wheaton, Illinois
  • Winnipeg, Manitoba

Exceptions in the United States

As you can see, the major part of the United States uses Central Daylight Time annually but there are some exceptions as well that don’t change their clocks from March to November. Some areas in the country differ from the average territories because they are split into different time zones. Therefore, there are some states that observe two different times at the same time. 

Here’s the list of exceptional territories in the United States in the terms of Central Daylight Time:

  • Alabama (Phenix City, Valley, Smiths Station, and Lanett) – the state uses Eastern Standard Time (EST) which is UTC – 5 hours. 
  • Florida – this state also uses the Eastern Standard Time (EST) except for Florida’s panhandle, including the city of Pensacola and Apalachicola River territories where CST and CDT are used.
  • Indiana – the southwestern and northwestern parts of Indiana remain in the Central and Daylight time zones while most of the state is in the Eastern time zone.
  • Kansas – the state (including Wallace, Sherman, Greeley, and Hamilton) doesn’t use CDT and CST.
  • Kentucky – the western half of the state uses CDT and CST while the rest observes Eastern Time.
  • Michigan –  Gogebic, Iron, Menominee, and Dickinson counties use CST and CDT while the rest observes Eastern Time. 
  • North Dakota – the south area of the Missouri river observes Mountain Time Zone (MST), while 75% of the state is in the Central Time Zone.
  • South Dakota – the western half of the state uses Mountain Time Zone (MST), and the eastern half uses Central and Daylight time.
  • Oklahoma – the entire state observes the Central Time except for the community of Kenton that unofficially uses MST.
  • Tennessee – the western and middle parts of the state use CST and CDT and the rest is in the Eastern Time Zone.
  • Texas – the state observes Central Daylight Time, except two counties – Hudspeth and El Paso that are in the Mountain Time Zone.

Interesting Facts About Time Zones

Now that you know everything there is to know about time zones and the CDT time zone, it’s time to read a few interesting and fun facts about time zones:

  • Central Daylight Time is, as its name suggests, a Daylight-Saving Time. Central Standard Time, on the other hand, is not. This means that while CDT is UTC-05:00, CST is just UTC-6:00. Don’t forget this when trying to schedule a call with someone in Texas or Alabama, especially if your own country does not observe Daylight Savings.
  • Saskatchewan, in Canada, does not change its time. In other words, this territory is under permanent daylight saving.
  • The change to CDT happens in the second Sunday of March, at 2 AM. The change back to CST happens on the first Sunday of November, at 2 AM.
  • There are time zones that have an offset that contains fractions of an hour. For example, Indian time is UTC+05:30. Another interesting thing to note is that India uses a universal hour all across its vast territory. So it’s always the same local hour everywhere in India. Nepal uses fractions of an hour in its UTC offset as well (Nepal time is UTC+05:45).
  • Not all territories advance their clock by one hour when transitioning to Daylight Saving Time. Lord Howe Island in Australia advances the lock by just 30 minutes instead of the usual hour.
  • Vladimir Putin deleted 3 of Russia’s 12 time zones. Now Russia has just 9 time zones, even though it is spread across no less than 12.
  • China has just one time zone (UTC+08:00), which makes this particular time zone very wide. In fact, it is the widest time zone on planet Earth, and it’s an agreement rather than a geographical reality.
  • Greenwich Mean Time (GMT) is the same as London time, but only during the winter. In summer, the United Kingdom observes Daylight Saving Time (GMT+01:00). And the British created GMT.
  • All over the world, Daylight Saving Time is now used in over seventy countries and the changes affect over one billion people every year. The exact dates of moving the clocks forward and backward change from country to country, but generally, it occurs in the months of March in the spring and October – November in the fall.
  • The idea of having a daylight savings time was first proposed in 1895 in New Zealand by an entomologist George Hudson who proposed that moving the clocks will give people more daylight hours after work. In 1916, the Germans had the same idea, but a different purpose: to save energy, and soon, the daylight savings time swaps were accepted in Canada and the US. 
  • Daylight savings time is irrelevant on the equator because of the Earth’s natural tilt. In the middle section of the planet, the daylight hours are about the same, so there is no point to move the clocks. Further North or South from the equator, however, the countries receive more or less daylight depending of the time of year, which is why it makes sense to move the clocks and have a little more daylight – this is especially important in the more Northerly territories where nights are long. 

DST – Daylight Saving Time

DST Daylight Saving Time

“Spring forward and fall back.” This statement’s relation to time is known the world over and holds significant meaning, especially for countries observing daylight saving time (DST). Daylight saving time represents an adjustment in time by moving forward one hour to increase the length of daylight in the evening, generally during the summer time. The practice is used for the summer because it robs one hour of daylight at the start of the day, rendering it impractical in winter. However, for people who follow the world clock, there is an added hour of daylight after regular work hours to engage in “daytime” activities of choice.

Although the concept of Daylight Savings Time may be familiar around the world, not all countries observe the DST. Curiously enough, some countries are split on the DST issue even more, for example, Australia, where some states adhere to the Daylight Savings and others do not. Generally, whether a country observes DST or not will largely depend on their geographical location: countries clustered around the equator have no need to switch to DST as around the circumference of the globe, it’s always 12 hours of daylight and 12 hours of darkness. Unlike in the North, around the equator, the days and nights do not grow shorter or longer regardless of season. The further from the equator, the more the length of days and nights change because of the Earth’s natural tilt. Around the Arctic circle, the nights are longer; around the Mediterranean, less so.

Whether your home country observes the DST or not, it’s handy to know your time around the world if you work or communicate with people from different countries. Time zone differences aside, there may be additional variation of time depending on the DST observations. For example, territories observing Central Daylight Time (CDT) will switch to Central Standard Time (CST) in winter. So if you’re trying to call someone in New Orleans, remember you’ll need to check their current local CDT time in summer and CST in winter.

To better understand the origins, history, and use of Daylight Savings Time around the world, let’s dig a little deeper.

History of Daylight Savings Time

Records prove the use of daylight saving time for roughly 100 years, dating back to the Roman period when people used water clock scales to account for longer summer days and shorter winter days. Interestingly, archaeologists have found evidence that earlier in human history, the sun’s schedule was the basis for developing daily schedules. In many ways, that makes sense: early humans, much like us, preferred to make good use of daylight hours instead of toiling in the dark.

Speaking of working under the candlelight: in Germany, the Daylight Savings time was first introduced during the World War I era in order to save energy and help the war effort. Burning electricity needlessly when natural daylight could be extended by one whole hour seemed inefficient to the Germans, so in 1916, Germany became the first country in the world to implement the Daylight Savings Time on scale.

However, it wasn’t the Germans who came up with the idea first. In 1895, a New Zealand entomologist George Vernon Hudson discovered he could save himself an entire two hours of working in the dark by ways of moving the clock forward in spring, when the sun sets later. Hudson was so enthusiastic about his discovery he wrote a paper to the Wellington Philosophical Society – and gained interest. Unfortunately, New Zealanders just weren’t ready for Hudson’s innovation, and the proposal was never carried out.

Almost at the same time – barely seven years later – an Englishman by the name of William Willet was struck by the same idea. Willett, a builder, was out for an early morning horse ride when he realized an entire nation could benefit from a simple moving of the clock one hour ahead to save daylight. He was so adamant he proposed his new way of looking at time to the British Parliament, and famous figures like Winston Churchill and Sir Arthur Conan Doyle actively supported the idea. The English Parliament, on the other hand, did not, and although Willett argued about the necessity of observing Daylight Savings Time until his death in 1915, it took England a while to warm up to the concept.

Canada, on the other hand, readily accepted the DST as early as 1908. It took another decade for the DTS concept to gain traction nationwide, but Canada, much like the US and the UK, soon followed Germany’s example because of the war years. Saving energy, it seemed, was on everybody’s priority list.

Today, the energy-saving aspect of DST is somewhat less important, but enjoying longer summer days is something people appreciate around the world.

How Does DST Work?

The most obvious thing about the mechanism of Daylight Saving Time is that we lose one hour when it starts but we gain one after it finishes. But it’s interesting to find out how exactly the DST works. 

As you probably already know, Daylight Saving Time usually starts in the spring. During this time, the population of the countries or regions that observe DST set their clocks forward by 1 hour. Therefore, part of the world skips one hour on the DST transition day. That’s what makes this one particular day so special – it consists only of 23 hours instead of 24. 

Generally, the transition happens at night in order to avoid confusion in society. Accordingly, people just sleep one hour less than their usual routine. Since one hour is not a big deal, our body and mind can somehow adjust to the change. Still, many people consider DST’s effect on our health very negative. But before we discuss its disadvantages, let’s focus on the positive things. Fortunately for those who work during the night, you will be able to leave work earlier on this one day.

For example, in the United States, Daylight Saving Time began at 2 a.m. on Sunday, March 13 in 2021. It will finish on Sunday, November 7 at 2 a.m. and people will have to turn their clocks back one hour. The easiest way to remember this mechanism is by using the expression “Spring forward, fall back”. On March 14 the US changed the time to “spring ahead” and on November 7 they will “fall back”. 

Why Do We Need Daylight Saving Time?

Even though the purpose of Daylight Saving Time is very clear at a first glance, the debates never end about its convenience. Does it really have significant benefits? Do we need DST at all? People often ask these and many other questions.

Daylight Saving Time or “Summer Time” as many people call it around the world, helps us to use daylight more effectively. In fact, the main purpose of changing the clocks during the summer months is to have a bigger day and shorter night. As a result, instead of waking up at night and finishing working or studying in the dark, the world has an opportunity to start the day when the sun has already risen and finish the main activities of the day before dusk. 

One of the main advantages of DST is that people have larger evenings during this period. Also, we can reduce the use of artificial light. Therefore, we can minimize energy consumption and reduce our costs. Besides, according to the studies, the crime rates usually drop during DST which may seem rather surprising but it’s a fact. Research also proves that DST can lead to fewer car crashes and road accidents. Considering all these beneficial effects, DST has to be a great way to make better use of natural daylight. However, research also shows the negative outcomes which is why we can’t say that observing DST is 100% advantageous. 

Problems with DST

Daylight Saving Time can certainly help us to save daylight but many countries still refuse to observe DST. Why do they hesitate? Is it really worth switching to “Summer Time”?

In fact, Daylight Saving Time is accompanied by serious mental and physical health issues, including increased risk of cardiovascular conditions, sleep disturbances, mood changes, and more. Not everybody finds it easy to adjust to the changes in their daily routine. The fact that it can interfere with our circadian rhythm is one of the reasons why people experience seasonal affective disorder and several other mental health conditions. 

Some of the other cons of switching to DST are the following:

  • Increased risks of a heart attack on the following Monday.
  • Feeling fatigued on the following Monday.
  • Inability to adjust to the change in time, resulting in decreased productivity and distress.
  • Negative effect on the eating habits of pets.

Can DST Save Energy?

People often use the argument of reducing the energy during Daylight Saving Time. But most times, it can’t really overcome its cons because studies show that DST doesn’t actually save energy, and even more, it has an opposite effect. The main purpose to introduce DST was to avoid wasting many candles for lighting at night. There would be more hours of daylight which could lead to the decreased need for artificial light. And indeed, a century ago it actually conserved a lot of electricity and fuel.

But what happened today? Is DST still capable of saving energy? Unfortunately, the answer isn’t positive. In fact, using computers, air conditioners, or phone chargers is an integral part of modern society. In the 21st century, it doesn’t really matter whether it’s day or night, everybody needs electricity to work or spend leisure time. Consequently, the amount of energy saved with DST is insignificant. 

DST’s Negative Impact on Health

At a first glance, delaying the clock for one hour shouldn’t be a big deal. But it turns out that the opponents of DST do have some rational reasons. A lot of studies proved that changing the time has a negative effect on our physical and mental health. First of all, Daylight Saving Time disrupts our circadian rhythm, meaning that it’s hard for our “body clocks” to adapt to the change. Also, the early evening after the end of the DST increases the risk of mood disorders such as depression. The reason is that the sun is the best source of vitamin D which is vital for our bodies. And the low levels of vitamin D increase the chances of depression. In the worst case, the lack of sunlight can even cause a seasonal affective disorder. 

Besides, DST increases the chance of heart attacks and cardiovascular disorders. Specifically, stroke rates are 8% higher in the first two days after the DST. As a result, the debates about the need for Daylight Saving Time continues and probably, it’s not going to stop any time soon.

Use of DST Around the World

Regardless of where a country is located geographically, the choice of observing the Daylight Savings Time is up to its people and government. Currently, around 70 countries use DST either nationwide or regionally; the three major countries that do not observe Daylight Savings are India, China, and Japan. 

Most commonly, DST is observed in North America, Europe, and parts of Asia as well as parts of South America and Oceania. Because the seasons are reversed in the Southern Hemisphere, they daylight savings time changes occur in winter rather than summer, and vice versa in the Northern Hemisphere.

Countries that currently observe the DST:

  • Bahamas
  • Bermuda
  • Canada, except Yukon, most of Saskatchewan, and parts of British Columbia (northeast), Nunavut (Southampton Island), Ontario (Atikokan) and Quebec (Le Golfe-du-Saint-Laurent)
  • Greenland
  • Haiti
  • Mexico: Baja California, and municipalities within 20 km of the U.S. border except in Sonora
  • Saint Pierre and Miquelon
  • Turks and Caicos Islands
  • United States, except Arizona (except Navajo Nation), Hawaii, and U.S. territories
  • Cuba
  • Akrotiri and Dhekelia
  • Albania
  • Andorra
  • Bosnia and Herzegovina
  • Faroe Islands
  • Gibraltar
  • Greenland, except Danmarkshavn and Thule Air Base
  • Guernsey
  • Isle of Man
  • Jersey
  • Kosovo
  • Liechtenstein
  • Monaco
  • Montenegro
  • North Macedonia
  • Northern Cyprus
  • Norway
  • San Marino
  • Serbia
  • Switzerland
  • Ukraine, except Crimea, Donetsk PR and Luhansk PR
  • United Kingdom
  • Vatican City
  • Moldova
  • Israel
  • Jordan
  • Lebanon
  • Palestine
  • Syria
  • Iran
  • Chile, except Magallanes Region
  • Paraguay
  • Australia: Australian Capital Territory, Jervis Bay Territory, New South Wales (except Lord Howe Island), Norfolk Island, South Australia, Tasmania and Victoria
  • New Zealand
  • Samoa
  • Fiji

DST Choices and Curiosities

Although most countries around the world readily accepted the idea of Daylight Savings in the first part of the twentieth century, many have subsequenlty abolished DST time changes. Most recently, a list of countries that stopped observing DTS includes Argentina, Armenia, Azerbaijan, Belarus, Brazil, Cook Islands, Egypt, Falkland Islands, Georgia, Hong Kong, Iceland, Iraq, Jamaica, Kazakhstan, Kyrgyzstan, Macau, Mongolia, Namibia, Russia, Sudan, Turkey, Uruguay, and Vanuatu. Some of these countries ditched DST altogether, while others accepted DST as their time standard year round. Permanent DST? Why not!

Within the European Union, the European Commission conducted several surveys to find out whether Europeans actually wanted the DST changes. In 2018, almost five million survey responders within the EU expressed they would rather not move the clock back and forth; interestingly, Germans were especially vocal about ditching the DST for good – in Germany, 84% survey participants said they‘d rather not adjust their clocks. However, the DST changes still persist in Europe, whether the locals enjoy the changes or not.

Similarly, United States is struggling with DST, too: several states have passed laws abolishing the Daylight Savings Time, but without the support of federal government, these laws aren’t valid. With the exception of Arizona and Hawaii, most states in the US follow the DST.

However, the Daylight Savings Time curiosities do not end here. To uncover some more fascinating DST information, we’ve compiled a list of Daylight Savings Time fun facts – make sure to read to the end of the article to find out why DST is especially beneficial for candy makers:

  • Although historically, the idea of Daylight Savings Time first occurred to the Romans and then, the famed New Zealand scientist, eighteenth-century US wasn’t far off, either. None other than Benjamin Franklin proposed the idea of moving the clocks forward in spring as early as 1784, when he wrote an essay called “An Economical Project for Diminishing the Cost of Light” in The Journal of Paris. Rumor has it, Franklin was unamused to be woken early by the noise in Parisian streets during his visit, and he also proposed that the use of longer daylight hours would save…candles. Now that’s a president with a strong economist’s mind.
  • Speaking of economy: while the idea that DST saves time is somewhat controversial, U.S. Department of Transportation conducted a study showing that DST cuts the nation’s electricity use by one percent. However, that’s just one study, and there are plenty of others showing the exact opposite and claiming that Daylight Saving Time actually increases electricity usage up to 4 percent. Which study was right, remains undecided.
  • DST is bad news for the television industry: if people did not move the clocks and got home when it’s already dark, nighttime TV shows would receive much more attention. However, as the clocks are moved forward and people are able to stay out longer, nobody wants to settle in and watch the TV – so much so that 2009 “American Idol” hit record low ratings because it was released immediately after the summer time change. Statistics show that prime-time TV show ratings drop by 10% when we change the time – and that’s probably good news if it means people are spending more time outdoors rather than slumped in front of their TVs.
  • Much like with lower TV show ratings, it seems the DST may have killed the drive – in movie theaters in the US. When the DST was widely adopted across the entire country in 1966, owners of drive-in movie theaters saw a major decline: movies could not start during daylight hours, and movies that weren’t starting during family-friendly time just didn’t attract big audiences. Is DST really to blame? Perhaps only time will tell.
  • More bad DST news: although clocks are typically only moved an hour or two, it can mess with children’s and teenagers’ sleep schedules so much that it affects their performance at school and their exam results. A study done by the Journal of Neuroscience, Psychology, and Economics revealed that there was a two-percent score drop in exam results when tests were being taken right after the time change.
  • This doesn’t just affect children and young people: adults often complain about the negative effects of DST changes, too. One study showed that workers sleep around forty minutes less on average right after the switch to DST, and it takes us weeks to adapt to new sleep cycles – so much so that DST changes and the resulting sleep deprivation is sometimes linked to higher car accident and depression rates.
  • Unsurprisingly, only 36% of Americans like the idea of DST, according to citizen surveys. More than half of survey respondents in the US do not believe that DST saves energy, and almost 20% admitted being late for work after the DST changes because they forget to adjust the clocks. In fact, the US even hosts a national movement called Lock the Clock, petitioning to abolish the use of DST altogether.
  • Despite complaints and criticism, DST does have one positive effect: a significant drop in crime. A study conducted in 2015 showed that crime rates drop in spring when the DST is introduced – apparently, robbers and burglars do not like operating in plain daylight.
  • In addition, DST once helped prevent a tragedy: in September 1999, terrorists in the West Bank failed to account for Israel’s time change and the planned bombing failed to kill the intended victims, ending the lives of three terrorists instead.
  • Most people assume DST begins at the stroke of midnight – but that’s not actually true. Daylight saving time begins at 2 am in the morning; this is done to delay people noticing it. If the clocks were changed at midnight, it would be more obvious, whereas at two in the morning, the change goes unnoticed as most people are asleep.
  • Curiously, DST negatively affects night owls more than morning people.
  • DST seems to induce mindless scrolling: according to one survey, people tend to browse the web and scroll their social media feeds at work more right after the DST change, likely owing to sleep deprivation. In addition, DST changes may be responsible for increased headaches. Ouch.
  • In the USD, DST wasn’t always…DST. During the World War I, it was known as the “fast time” and “war time”. Let’s just agree that Daylight Saving sounds much better.
  • There is a popular myth that DST was introduced to help farmers produce more. This couldn’t be further from the truth: as early as the 1960s, farmers have been complaining that the DST changes negatively affect the animals, namely cows who are very sensitive to exact milling times. And if that wasn’t enough, harvesting wheat and other grain is most productive right after the morning dew evaporates… so despite best intentions, DST just isn’t working for the farmers.
  • On the other hand, later sunsets mean… more candy sales. How? Halloween: because of DST, kids can stay up late and go trick-a-treating longer during Halloween, and that’s good news for the candy and chocolate bar industry.