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


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)


  • 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.