The Mountain Standard Time Zone (MST) is a geographic region that keeps time by subtracting seven hours from Coordinated Universal Time (UTC). In the United States, the following states are part of the Mountain Standard Time Zone:

• New Mexico
• Wyoming
• Utah
• Colorado
• Montana

Additionally, the southwestern quadrant of North Dakota, the western half of South Dakota, the western third of Nebraska, the two westernmost counties in Texas, and the bulk of Idaho are part of the Mountain Standard Time Zone. Four counties in Kansas are part of the Mountain Standard Time Zone. Also, one county in Oregon is divided between the Mountain and Pacific Time Zones; most of the county in question (Malheur County) observes Mountain Time because of its economic ties to southwestern Idaho. Likewise, the town of West Wendover, Nevada observes Mountain Time because of its close economic ties with central Utah.

Arizona is part of the Mountain Standard Time Zone, but does not observe Daylight Saving Time, a period of time between April and October in which the Mountain Standard Time Zone keeps time by subtracting six hours from UTC. However, the Navajo Nation, the bulk of whose area is within Arizona, observes Daylight Saving Time throughout its territory.

Other parts of the world that keep time by subtracting seven hours from UTC include the Canadian provinces of Alberta, Northwest Territories, and the part of Saskatchewan immediately surrounding Lloydminster, as well as the Mexican states of Baja California Sur, Chihuahua, Nayarit, and Sinaloa, along with Sonora, which does not practice DST.

See also

• Time zone
• Hawaii-Aleutian Standard Time Zone
• Alaska Standard Time Zone
• Pacific Standard Time Zone
• Central Standard Time Zone
• Eastern Standard Time Zone
• Atlantic Standard Time Zone
• Newfoundland Standard Time Zone

Sources

• http://www.travel.com.hk/region/timezone.htm
• http://geography.about.com/library/misc/ntimezones.htm
• http://aa.usno.navy.mil/faq/docs/us_tzones.html
• http://www.worldtimezone.com/time-canada12.html