North American time zones:

MST - Mountain Standard Time

Time zone offset: UTC - 7 hours

Note that most places observe daylight saving time/summer time during summer, and are therefore using MDT instead in the summer. See below for details.

Time zone abbreviations: MST, HNR

Email time zone indicator: -0700

An email sent from someone in the MST time zone will have the time zone listed as "-0700" in the headers of the email. (However, "-0700" does not have to be in MST, as other time zones could have the same UTC offset).

Where and when is MST observed?

MST is used during winter in these US states (MDT during summer)

• Arizona - Navajo Nation only
• Colorado
• Idaho - most of the state except western counties
  Benewah, Bonner, Boundary, Clearwater, Kootenai, Latah, Lewis, Nez Perce, Shoshone and north part of Idaho
• Kansas - some western counties only
  Greeley, Hamilton, Sherman and Wallace
• Montana
• Nebraska - western counties
  Arthur, Banner, Box Butte, Chase, Cheyenne, Dawes, Deuel, Dundy, Garden, Grant, Hooker, Keith, Kimball, Morrill, Perkins, Scotts Bluff, Sheridan, and Sioux and the western part of Cherry
• New Mexico
• North Dakota - South-Western parts
  counties of Adams, Billings, Bowman, Golden Valley, Grant, Hettinger, Mercer, Slope and Stark, and southern parts of Dunn and McKenzie, most of Morton and Sioux counties
• Oregon - parts of Malheur county only
  rest of Oregon is PST/PDT
• South Dakota - western counties
  Bennett, Butte, Corson, Custer, Dewey, Fall River, Haakon, Harding, Jackson, Lawrence, Meade, Mellette, Pennington, Perkins, Shannon, Todd, and Ziebach, and the western parts of Jones and Stanley
• Texas - a few counties in west
  El Paso and Hudspeth and part of Culberson
• Utah
• Wyoming

MST is used during winter in these Canadian provinces (MDT during summer)

• Alberta
• British Columbia - a few eastern communities
  Cranbrook, Golden, Invermere
• Northwest Territories
• Saskatchewan - only Lloydminster

MST is used during winter in these Mexican states (MDT during summer)

• Baja California Sur
• Chihuahua
• Nayarit
• Sinaloa

MST is used all year

• Dawson Creek area, British Columbia
• Most of Arizona
  except Navajo Nation which use MDT during summer
• Sonora

Example locations in MST

• Chihuahua - during winter
• Phoenix - all year

Other time zones in North America

• NST - Newfoundland Standard Time
• NDT - Newfoundland Daylight Time
• AST - Atlantic Standard Time
• ADT - Atlantic Daylight Time
• EST - Eastern Standard Time
• EDT - Eastern Daylight Time
• CST - Central Standard Time
• CDT - Central Daylight Time
• MDT - Mountain Daylight Time
• PST - Pacific Standard Time
• PDT - Pacific Daylight Time
• AKST - Alaska Standard Time
• AKDT - Alaska Daylight Time
• HAST - Hawaii-Aleutian Standard Time
• HADT - Hawaii-Aleutian Daylight Time

Time zones in other regions

• Australia
• Europe
• Military

Related links

• Time zone abbreviations world-wide
• The World Clock - Time Zones - current time around the world
• The World Clock - Time Zone Converter - Convert between time zones
• World Clock - North America - current time in North America