EST – Eastern Standard Time Zone

Time zones have been created for a wide variety of social, legal and commercial reasons. 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. To make things simple, all time zones are defined by the Coordinated Universal Time (UTC). But most people don’t know exactly what a time zone is. 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. So let’s explain what time zones are, what UTC is and what it is used for, and then analyze the EST time zone. You can also find some very fun to read facts about time zones towards the bottom of the page.

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. All time zones are UTC plus or minus some time (usually one of more hours). In other words, EST for example is 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 are entirely in one large time zone (China, for example).

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 an 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 in the first Sunday of November.

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. Also, EST time is being used in Panama, in Acre and part of Amazonas (both in Brazil), in Colombia, in Ecuador, and in the Caribbean Islands (Cuba included).

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

Also, 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. 

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.

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. And China has almost 1.38 billion people (as of 2016).

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 Zone, Central Time Zone, Eastern Time Zone, and Pacific Times Zone.
  • UTC, also known as Greenwich Mean Time, is centered at 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.
  • 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 12 time zones. However, in 2010, 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.
  • 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. This happens because of time zone differences and is the cause for jet lag.

GMT – Greenwich Mean Time

We all hear the term GMT, or Greenwich Mean Time. In general, we hear it when people refer to their time zone. And many people say that they are in UTC time when what they want to say is that they are in GMT time. There is a difference between GMT and UTC – and a pretty big on to say the least. The problem is that most people don’t know exactly what a time zone is and what it is being used for. They also don’t know what the UTC standard is and what the UTC offset is used for. So let’s talk about time zones, UTC, UTC offset, and the GMT time zone specifically. You can also find a list of interesting facts about time zones at the end of this article.

What Are Time Zones Exactly?

Without time zones, it would be impossible for all countries on Earth to have the sun at the highest point in the sky at noon. Why? Because Earth rotates by 15 degrees every hour. This is exactly why time zones were created. Basically, the planet was split into 24 slices of 15 degrees each. Each slice is a time zone. And all time zones are coordinated using the Coordinated Universal Time (UTC) standard. This is why Eastern Standard Time is UTC-5 and Pacific Standard Time is UTC-7. The difference between a given time zone and UTC time is called the UTC offset. In other words, Eastern Standard Time has a UTC offset of minus 5 hours (UTC-5). But remember, UTC is a time standard. GMT, on the other hand, is a time zone. So it is incorrect to say that you are in the UTC time zone. Yes, UTC and GMT are being used interchangeably at the time of writing. But this does not mean it is correct.

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. Again, it is important to note that UTC and Greenwich Mean Time (GMT) are not the same. GMT is a time zone and UTC is a time standard. 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.

A Short History of GMT

Introduced to help with naval navigation when travelling around the world, GMT was once the international civil time standard. At present time, this function is being fulfilled by the Coordinated Universal Time standard. However, in the UK 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. 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. 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 places 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.

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
  • The 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):

  • The 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. 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.

Interesting Facts About Time Zones

Now that you know everything there is to know about Greenwich Mean Time and about UTC and the UTC offset, let’s present a few very interesting things about time zones:

  • 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.
  • 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).
  • 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.”
  • 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.
  • GMT is also called Western European time and sometimes Greenwich Mean UT (an abbreviation of Universal Time).
  • Several countries, such as Belgium and Canada use Greenwich Mean Time to define their local time.
  • China is huge, yet it only has one single time zone: GMT+8:00. On the other hand, France has 12 different time zones.
  • 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.
  • 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. 
  • 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.
  • Speaking of India, this country – even though large – uses a single time zone (Indian Standard Time). China has a single time zone as well, and it’s called Beijing Time. This poses a problem because China is wide, and it should be in several times zones, not just in one. 

EDT (Eastern Daylight Time) 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 UTC offsets? And did you know that UTC is not a time zone? The reality is that time zones are extremely important to everyone. They greatly influence social and commercial activity. They even influence military communications and operations. So, let’s take a look at what the EDT time zone is and how it relates to the other time zones on Earth. Also, we will list the most important countries and the major cities that are in EDT. It is important to note that these countries and cities are not in the EDT time zone all year round. Some of them observe Daylight Saving Time, which means they enter another time zone during summer months. You’ll also find a list of fun facts about time zones towards the end of this article.

What Exactly Is a Time Zone?

So, 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 sphere. Only half of it faces the Sun. And because it rotates, various countries observe noon at different hours throughout the day. To coordinate time and to help people and businesses, the Earth was split into 24 time zones. 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. And all time zones are regulated after UTC.

What Is UTC and How It Differs From EDT?

UTC, an abbreviation for Coordinated Universal Time, is not a time zone. UTC is a time standard. In fact, UTC is the standard by which all time is coordinated and regulated. Yes, most people use UTC to refer to a time zone. However, at least at the time of writing, the time zone that uses UTC time is called GMT (Greenwich Mean Time). The difference of time between UTC and the time in a certain area is called the offset. For example, EDT (Eastern Daylight Time) is UTC-04:00. This means that Eastern Daylight Time has a negative offset of 4 hours. Then it is 8 PM in the EDT time zone, it is just 4 PM in the GMT time zone. And remember that there are also two variations of EDT: EDST (or the Eastern Daylight Savings Time) and NAEDT (or the North American Eastern Daylight Time). All time zones are coordinated by UTC, this is why there is such a thing as an UTC offset. The difference between two countries, one in UTC+4 and one in UTC-4, is of 8 hours. It’s actually pretty simple to calculate time if you know that UTC offsets of the various countries on Earth. And you can find this information everywhere online.

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, 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 normal 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

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.
  • 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.
  • 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.
  • Not all countries observe Daylight Savings Time. Examples include most of Africa, Argentina, Peru, and even parts of Australia.
  • 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.

PST – Pacific Standard Time

Everyone has heard about time zones, but not many people know exactly why they were created and why they are important. A time zone is basically a region of the globe where the same standard time is used. In other words, all the countries in a time zone keep the same time. It is very important to note that times zones are very useful for commerce because they help countries that are close to each other to keep the same time. Communication becomes much easier when both parties are in the same time zone. In addition, time zones are important for military operations. However, keep in mind that the military has different names for the various times zones. For example, Z (or Zulu) Time is Coordinated Universal Time (UTC) in military jargon. Now that we have explained what a time zone is and why it is important, let’s talk about what UTC and UTC offset are. Then we will discuss the PST (also known as Pacific Standard Time) time zone specifically.

Let’s Talk About UTC and Its Importance

Did you notice how many people say that they are in the UTC time zone? This is not correct though. UTC, short for Coordinated Universal Time, is a time standard. In fact, it is the time standard that coordinates all time across all time zones. What people mean to say when they are saying that they are in the UTC time zone is that they are in the GMT time zone. GMT is basically UTC+00:00. In other words, GMT uses the time of UTC. There is no UTC offset. Other countries in other time zones have various UTC offsets. For example, PST is UTC-08:00. Pacific Standard Time is 8 hours behind UTC. This is the offset. In general, offsets are whole hours. However, some countries use fractions of an hour in their offset. India is UTC+05:30. Nepal goes one step further, using a standard time that is UTC+05:45.

What Is PST?

PST (also known as Pacific Standard Time or simply Pacific Time) is 8 hours before Coordinated Universal Time (UTC). As stated previously, UTC is the primary time standard on Earth, which means it regulates all of the other time standards. In other words, all of the different time zones are an offset of the Coordinated Universal Time. It is important to note that PST has two names: Pacific Standard Time and Pacific Daylight Time. Pacific Standard Time, as we mentioned earlier, is UTC-8 (8 hours before UTC). On the other hand Pacific Daylight Time is UTC-7 and is used only during daylight saving time. Daylight Saving Time is observed during the summer months and is designed to increase the time humans can be active during daylight.  Daylight Saving Time starts on the second Sunday of March and end on the first Sunday of November. It starts and ends at 2 in the morning (AM). 

Countries That Are in Pacific Standard Time

PST covers United States, Canada and Mexico but not in their entirety. In the United States, the Washington and California states are entirely in Pacific Standard Time. Most of the Oregon and Nevada states are also in PST, while just portions of Idaho are included in this time zone. These three states are split between PST and Mountain Time Zone. Alaska is also split between PST and the Alaska Time Zone.

In Canada, only one territory is entirely in PST: Yukon. British Columbia and the Northwest Territories are split between PST and the Mountain Time Zone.

In Mexico, Pacific Standard Time encompasses just Baja California and Colima (Clarion Island more specifically). It is important to note that in Mexico, the Pacific Time Zone is called Zona Noroeste.

Important Cities in PST

According to estimates, more than 52 million people live inside the PST time zone. California is by far the biggest area in PST, with three major cities: San Diego, Los Angeles and San Jose. San Francisco is also in PST, with more than 700,000 residents. Las Vegas, Portland and Seattle are the three other major American cities that are in the Pacific Time Zone. In Mexico, Baja California and Tijuana are in PST, while in Canada Vancouver is the major city that contributes around 400,000 residents to the total number of people residing in the PST time zone. If you think 52 million people are a lot for a time zone, think about China. China has a single time zone, and the country has a population of 1.38 billion people as of 2016. India has a single time zone as well. Russia on the other hand is split between 9 time zones. It should have been split between 12 time zones, but president Putin decided 3 of the time zones must go to bring some areas of Russia closer to the Moscow time.

Interesting Time Zone Facts

Now that you know that UTC and the UTC offset are, and how PST fits into the picture, it’s time to take a look at some of the most interesting facts about time zones: 

  • It is important to note that broadcasting companies are directly affected by time zones. North American broadcasters must take into consideration the various time zones and schedule television programming accordingly. Another variation is given by the daylight saving time.
  • Some countries use an offset that is multiple of 30 minutes. While most people think that time zones are determined by whole hours, several countries in Southern Asia (India, to be more specific), are in the UTC+5:30 Time Zone, or 13 hours and 30 minutes ahead of PST. Iran is UTC+3:30 and Afghanistan is UTC+4:30. And to make things even more complicated, Nepal is UTC+5:45.
  • UTC+12 and UTC-12 are the same time zone, but with a different date. The difference between countries in these two time zones is of 24 hours, or one whole day.
  • One could have two birthdays in 24 hours by travelling between different time zones. Also, one could skip Christmas doing the same. There are areas where a quick flight can force people to adjust their clocks with as much as 4 hours.
  • Russia spans over 11 time zones geographically. However, Putin decided to abolish two of them in 2010 so that several regions could catch up with Moscow and be on the same time as the capital city. Also, Crimea skipped ahead two hours when it was annexed by Russia in 2014.
  • India is a huge country that maintains a single national time zone, which is UTC+5:30. And Hawaii doesn’t adhere to Daylight Saving Time at all. The time zone of Hawaii is GMT-10 all year round.
  • Remember that your wristwatch will not know when you are in a different time zone, so you will have to adjust it manually. Your computer and your smartphone, on the other hand, are capable of adjusting their time accordingly automatically.
  • Jet lag is caused by the time zone differences. When you travel quickly between various time zones, the time zone differences will disturb your circadian cycle. You may leave early in the morning and when you arrive at the destination, it can be late at night. Your body will take some time to get used to this.
  • Did you know that the United Kingdom, who has invented GMT (Greenwich is in the UK), is not in the GMT time zone all year round? British observe Daylight Saving Time, which means that they are actually in BST (which is UTC+01:00) during the summer months. They are in GMT though during the winter months.

UTC Time

Most people don’t know what UTC is and what times zones are. To shed light on the matter, let’s talk about what time zones really are, what UTC is, and then list the major countries and cities in UTC. Also, let’s see the differences between UTC and Greenwich Mean Time and then list some fun time zone facts. And did you know that UTC is not a time zone? Let’s see why!

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 time zone. As you can imagine, noon is at different times in each country, which means that noon (12 AM) would be observed at different times from country to country. Without a standard time that all countries in a time zone must observe, the countries would never observe the same time. This has many implications. Time zones are very important for commercial and social activities. 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. Also, 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.

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. Even though this time standard started being used from the start of 1960, it was officially adopted later, in 1967. Of course, the time standard has undergone several adjustments over time. 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? 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. And another thing to keep in mind is that UTC will never change for DST (Daylight Saving Time).

UTC and Greenwich Mean Time: The Differences

Many people say that they live in UTC time zone. This is, in fact, an incorrect statement. Why? Because UTC is a time standard, not a time zone. What they should be saying 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). The plus sign 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 times zones. Colorado is in UTC-07:00, while California, Nevada and Oregon are in UTC-08:00. Samoa 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. The differences in time between various countries on Earth can be huge. And keep in mind that GMT will never change for DST (Daylight Saving Time). However, some countries who 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 it, BST time is 1 hour ahead of GMT time.

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 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 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:

  • London
  • Casablanca
  • Dublin
  • Porto
  • Bissau
  • Lisbon
  • Ponta Delgada
  • Ittoqqortoormiit
  • Accra
  • Reykjavik

Interesting Time Zone Facts

Even though UTC is a time standard and GMT is a time zone, UTC is being used even by official sources. It is expected that UTC will replace GMT in the near future. So it is not a big mistake to say that you are in a UTC time zone. 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.
  • 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.
  • 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.
  • 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.
  • 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.

CDT – Central Daylight Time

Most people know what time zone they are in. However, they don’t really understand what a time zone is. Also, they don’t know that a time zone is different from a time standard. This is exactly why so many people say they are in the UTC time zone, when they should be saying that they are in the GMT time zone. Even though GMT and UTC are used interchangeably, they are not the same. So, to makes matters simple, let’s see what a time zone really is, what UTC and the UTC offset is, and then talk about the CDT time zone. Of course, 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. Towards the end of the article you will find some very interesting, and fun facts about time zones.

What Is a Time Zone?

Let’s begin by explaining what a time zone really is. As you probably know already, it can’t be noon at the same time all over the world. The Earth is a sphere which rotates. This means that different regions observe noon at a different time. When it’s night in one region, it may be noon in another. This is why time zones have been created. The Earth has been split into 24 slices. Across each slice, time is kept exactly the same. In other words, it will be 12 AM at noon everywhere in a time zone. Keeping time this way offers a lot of benefits to people, companies, and even to the military. 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. But let’s talk about UTC and the UTC offset for a bit.

What Is UTC and the UTC Offset?

UTC stands for Coordinated Universal Time. It is the standard after which all time zones adjust their time. And UTC is not a time zone, remember. It is a time standard. This means that when you say you are in the UTC time zone, you are somewhat wrong. You are in the GMT time zone, which has no UTC offset (GMT is UTC+00:00). The UTC offset is the number of hours between a specific time zone and the UTC time. For example, CDT (an abbreviation for Central Daylight Time) is UTC-05:00. In other words, Central Daylight Time is 5 hours behind Coordinated Universal Time. If another country is in a UTC+05:00 time zone, the time difference between you and people in that country would be of 10 hours. The UTC and the UTC offset are used to quickly calculate the time in any region of the planet, without having to worry about solar time.

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 used during the summer months. In the winter, many of the territories covered by CDT switch to the CST (Central Standard Time) time zone.

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.

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

Interesting Facts About Time Zones

  • Now that you know everything there is to know about time zones, UTC and UTC offset, 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.
  • 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 zone, 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.
  • 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.