Home   Time Zones   Abbreviations   MDT – Mountain Daylight Time

Mountain Daylight Time (MDT)

Also known as: Mountain Time (MT) and Mountain Standard Time (MST)

No locations currently on MDT. Would you like to see MST?

North America: MDT is currently not observed because locations are on standard time and are observing MST.

Time zone map of MDT
No locations currently on MDT.
Observes MDT part of the year.
Areas with same time currently (UTC -6).
No locations are currently on MDT – Mountain Daylight Time.
Observes MDT – Mountain Daylight Time part of the year, but not currently.
Currently has same time zone offset as MDT (UTC -6) but different time zone name.

Mountain Daylight Time (MDT) is 6 hours behind Coordinated Universal Time (UTC). This time zone is a Daylight Saving Time time zone and is used in: North America.

See full time zone map

What Is Mountain Daylight Time?

Mountain Daylight Time is the second westernmost time zone in the United States and Canada. It is also used in Mexico.

It covers all or parts of 13 states in the US and five provinces or territories in Canada.

The MST time zone is the least populated time zone in the USA. It spans from northern Canada to Mexico.

In North America, Mountain Daylight Time shares a border with Central Daylight Time (CDT) in the east and with Pacific Daylight Time (PDT) in the west.


Mountain Daylight Time (MDT) is a North American time zone in use from the second Sunday in March to the first Sunday in November during Daylight Saving Time (DST). Mountain Standard Time (MST) is used during the remainder of the year.

MDT Is the Mountain Time Zone

In everyday usage, MDT is often referred to as Mountain Time (MT) or the Mountain Time Zone. This can add a bit of confusion as the term Mountain Time does not differentiate between standard time and Daylight Saving Time, so Mountain Time switches between MST and MDT in areas that use DST during part of the year.

Most North American time zones also have generic terms, including Pacific Time (PT), Central Time (CT), Eastern Time (ET), and Atlantic Time (AT).

Converting Mountain Time to Other US Time Zones

Where and When is MDT Observed?

North America

US states using MDT in the summer and MST in the winter:

Canadian provinces/territories using MDT in the summer and MST in the winter:

Mexican states using MDT in the summer and MST in the winter:

This time zone is in use, but not observed in any location at this time.

Other Time Zones in UTC -6

Some time zones exist that have the same offset as MDT, but can be found under a different name: