In Canada, Mexico, and the United States, this time zone is generically called Mountain Time (MT). Specifically, it is Mountain Standard Time (MST) when observing standard time, and Mountain Daylight Time (MDT) when observing daylight saving time. The term refers to the Rocky Mountains.
On September 24, 2020, Yukon switched to the Mountain Standard Time year-round. Previously, the territory had used the Pacific Time Zone with daylight saving time: UTC−8 in winter and UTC−7 in summer.[5]
On March 8, 2026, most of British Columbia in the Pacific Time Zone adopted UTC−7 year-round but continue to call their time zone "Pacific Time". Southeastern parts of the province (near the Alberta border) continue to observe daylight saving time: UTC−6 in the summer and UTC−7 in the winter.[6]
Alberta observed Mountain Time with daylight savings until 2026 when it switched to Central Time year-round.
As of October 30, 2022, Mexico abandoned daylight saving time, with certain exceptions.
The following states have an offset equal to Mountain Standard Time, there called the Zona Pacifico (Pacific Zone):
The communities of Jackpot, Jarbidge, Mountain City, and Owyhee unofficially observe Mountain Time, although they are officially within the Pacific Time Zone.[7]
Five states are split between the Mountain Time Zone and the Central Time Zone. The following locations observe Mountain Time:
↑The specification for the Mountain Time Zone in the United States is set forth at 49 CFR 71.8.[2] The boundary between Central and Mountain time zones is set forth at 49 CFR 71.7,[3] and the boundary between Mountain and Pacific time zones is set forth at 49 CFR 71.9.[4]
↑"Adopting permanent daylight saving time". BC Gov News. Government of British Columbia. March 2, 2026. Retrieved March 2, 2026. At that point, the transition to Pacific time, the name of B.C.'s new time zone, will be complete. Pacific time will be set seven hours behind co-ordinated universal time (UTC−7), matching the current offset used during daylight saving time.
