Mountain Time Zone

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Mountain Standard Time (MST) is UTC-7 Mountain Daylight Time (MDT) is UTC-6

The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time (UTC-7) during the short days of autumn, winter and spring, and by subtracting six hours during daylight saving time in the spring, summer, and early autumn (UTC-6). The clock time in this zone is based on the mean solar time of the 105th degree meridian west of the Greenwich Observatory.

In the United States and Canada, this time zone is generically called Mountain Time (MT). Specifically, it is Mountain Standard Time (MST) when observing standard time (Winter), and Mountain Daylight Time (MDT) when observing daylight saving time.

The zone is one hour ahead of the Pacific Time Zone and one hour behind the Central Time Zone.

In some areas, starting in 2007, the local time changes from MST to MDT at 02:00 LST to 03:00 LDT on the second Sunday in March and returns at 02:00 LDT to 01:00 LST on the first Sunday in November.

1 Canada
2 Mexico
3 United States
4 Major metropolitan areas
5 See also
6 Sources

[edit] Canada

The following provinces and areas are part of the Mountain Time Zone:

Alberta
the Northwest Territories (except for Tungsten)
the Kitikmeot Region of Nunavut
portions of southeastern and northeastern British Columbia
the area of Saskatchewan immediately surrounding the city of Lloydminster

[edit] Mexico

The following states are part of the Mountain Time Zone:

Baja California Sur
Chihuahua
Nayarit
Sinaloa
Sonora - always on MST - no daylight saving time

[edit] United States

The following states or areas are part of the Mountain Time Zone:

Arizona - always on MST - no daylight saving time except in Navajo reservation
New Mexico
Wyoming
Utah
Colorado
Montana
Idaho (except northern panhandle)
Eastern Oregon/Malheur County
the southwestern quadrant of North Dakota
the western half of South Dakota
the western third of Nebraska
the two westernmost counties in Texas
four counties in Kansas (Greeley, Hamilton, Sherman, and Wallace)
the Nevada town of West Wendover

Arizona does not observe Daylight Saving Time. However, the Navajo Nation, the bulk of whose area is within Arizona, observes Daylight Saving Time throughout its territory. The Hopi Reservation, an enclave inside the Navajo Nation, does not observe Daylight Saving Time.