Difference Between Mountain Time and Eastern Time (With Table)

North America has a total of six time zones, two of which are Mountain time and Eastern Time. It is important to take note of them, especially for non-natives who plan on travelling through the place. The task is not difficult since both Mountain time and Eastern time function in reference to the Coordinated Universal Time (UTC). However, there are numerous differences between the two zones.

Mountain Time vs Eastern Time

The difference between Mountain time and Eastern time is that mountain time, which is formally known as Mountain Standard Time (MST) is seven hours behind UTC, which means that seven hours must be deducted from UTC to calculate it. Meanwhile, eastern time or Eastern Standard Time (EST) is only 5 hours behind the UTC. So, five hours need to be deducted from UTC to calculate it.

Mountain Time, however, has several variations. It is seven hours behind only when standard time is being practised. This is during autumn and winter. When daylight saving time is in effect, it keeps time six hours behind the UTC. This means that six hours need to be deducted from UTC to calculate it during spring and summer.

The case for eastern time is pretty much similar to mountain time. However, it is only during the standard time that five hours need to be deducted from UTC. When daylight saving time is in effect, it works four hours behind the UTC. So, people who follow eastern time need to set their clocks differently for various reasons.

Comparison Table Between Mountain Time and Eastern Time

Parameters of ComparisonMountain TimeEastern Time
AbbreviationsMountain Time (MT) is formally called Mountain Standard Time (MST) and Mountain Daylight Time (MDT) as well.Eastern Time (ET) is formally called Eastern Standard Time (EST) and Eastern Daylight Time (EDT) as well.
LocationIt covers parts of Mexico, five provinces in Canada and 13 states in the US.It covers Mexico, Central America, the Caribbean, 3 provinces in Canada, 23 states in the US.
PopulationIt is used by only 6.7% of the total population.It is used by 47.6% of the total population.
During Standard TimeIn autumn and winter, it is calculated by deducting seven hours from UTC. During this period, it is calculated by deducting five hours from UTC.
During Daylight Saving TimeIn spring and summer, it is calculated by deducting six hours from UTC.During this period, it is calculated by deducting four hours from UTC.

What is Mountain Time?

Mountain Time covers a smaller portion of the population as compared to Eastern Time. It spans across parts of Mexico, five provinces in Canada and 13 states in the US. Essentially, it keeps time with reference to the mean solar time at the 105th meridian. This is located to the west of the Greenwich Observatory.

Mountain Time is always calculated relative to the Coordinated Universal Time. It is always behind the UTC by dint of its western location. However, it has clear distinctions for when standard time is in effect during autumn and winter, as well as when daylight saving time is in effect during spring and summer.

For autumn and winter, the time zone is referred to as Mountain Standard Time (MST). During this period, it works seven hours prior to the UTC. This means that it must be calculated by deducting seven hours from the Coordinated Universal Time (UTC-7).

Meanwhile, mountain time is referred to as Mountain Daylight Time (MDT) during the spring and summer seasons. This is the period when daylight saving time is in full effect. MDT works six hours prior to UTC. Therefore, it must be calculated by deducting six hours from the UTC (UTC-6).

What is Eastern Time?

Eastern Time covers a larger population than the former. While mountain time is only used by 6.7% of the total population, eastern time is used by a staggering 47.6%. This is the most used time zone across the world. It spans across Mexico, Central America, the Caribbean, 3 provinces in Canada, 23 states in the US.

Like mountain time, eastern time is calculated relatively to UTC. It even has distinctions for a standard time and daylight-saving time. However, the time zone is located on the east side of mountain time. Therefore, it keeps time later than it. In general, eastern time functions 2 hours later than mountain time.

For autumn and winter, the time zone is referred to as Eastern Standard Time (EST). Here, the time is kept five hours prior to the UTC. This means that it must be calculated by deducting five hours from the Coordinated Universal Time.

Furthermore, in spring and summer, eastern time is referred to as Eastern Daylight Time (EDT). During this period, the time is calculated by deducting four hours from the UTC. So, people move their watches one hour forward, generally on the first Sunday of November. On the second Sunday of March, watches must be moved back by one hour.

Main Differences Between Mountain Time and Eastern Time

  1. Mountain Time (MT) is formally called Mountain Standard Time (MST) and Mountain Daylight Time (MDT) whereas Eastern Time (ET) is formally called Eastern Standard Time (EST) and Eastern Daylight Time (EDT).
  2. Mountain time covers parts of Mexico, five provinces in Canada and 13 states in the US whereas eastern time covers Mexico, Central America, the Caribbean, 3 provinces in Canada, 23 states in the US.
  3. Mountain time is used by only 6.7% of the total population whereas eastern time is used by 47.6% of the total population.
  4. In the effect of standard time, MST is calculated by deducting seven hours from UTC whereas during the same period, EST is calculated by deducting five hours from UTC.
  5. In the effect of daylight saving time, MDT is calculated by deducting six hours from UTC whereas during the same period, EDT is calculated by deducting four hours from UTC.

Conclusion

Mountain time and eastern time are calculated with reference to the UTC, however, they have several differences between them. Firstly, mountain time is used by a far smaller chunk of the total population. It even spans through a smaller area as compared to eastern time.

Another notable difference is that mountain time is always two hours behind eastern time. This is because of its westward location to eastern time and the Greenwich Observatory. Both of them are even calculated differently. While MST and MDT are calculated by deducting seven and six hours respectively from UTC, EST and EDT are calculated by deducting five and four hours

References

  1. https://www.journals.uchicago.edu/doi/abs/10.1086/227631
  2. https://dl.acm.org/doi/abs/10.1145/1017068.1017073
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