Mountain Time Zone

  (Redirected from Mountain Standard Time)

The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time (UTC) when standard time (UTC−07:00) is in effect, and by subtracting six hours during daylight saving time (UTC−06:00). The clock time in this zone is based on the mean solar time at the 105th meridian west of the Greenwich Observatory. In the United States, the exact specification for the location of time zones and the dividing lines between zones is set forth in the Code of Federal Regulations at 49 CFR 71.[a]

Mountain Time Zone
time zone
Timezoneswest.PNG
  MST or UTC−07:00
UTC offset
MSTUTC−07:00
MDTUTC−06:00
Current time
05:20, December 4, 2020 MST [refresh]
Observance of DST
DST is observed in some of this time zone.

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, and Mountain Daylight Time (MDT) when observing daylight saving time. The term refers to the Rocky Mountains, which range from British Columbia to New Mexico. In Mexico, this time zone is known as the tiempo de la montaña or zona Pacífico ("Pacific Zone"). In the US and Canada, the Mountain Time Zone is to the east of the Pacific Time Zone and to the west of the Central Time Zone.

In some areas, starting in 2007, the local time changes from MST to MDT at 2 am MST to 3 am MDT on the second Sunday in March and returns at 2 am MDT to 1 am MST on the first Sunday in November.

Sonora in Mexico and most of Arizona in the United States do not observe daylight saving time, and during the spring, summer, and autumn months they are on the same time as Pacific Daylight Time.[4] The Navajo Nation, most of which lies within Arizona but extends into Utah and New Mexico (which do observe DST), does observe DST, although the Hopi Nation, as well as some Arizona state offices lying within the Navajo Nation, do not.

The largest city in the Mountain Time Zone is Phoenix, Arizona; the Phoenix metropolitan area is the largest metropolitan area in the zone.

CanadaEdit

Only one Canadian province is fully contained in the Mountain Time Zone:

One province and one territory are split between the Mountain Time Zone and the Pacific Time Zone:

One territory and one province are split between the Mountain Time Zone and the Central Time Zone

MexicoEdit

The following states have the same time as Mountain Time Zone:

United StatesEdit

Six states are fully contained in the Mountain Time Zone:

Three states are split between the Mountain Time Zone and the Pacific Time Zone. The following locations observe Mountain Time:

Five states are split between the Mountain Time Zone and the Central Time Zone. The following locations observe Mountain Time:

See alsoEdit

NotesEdit

  1. ^ The specification for the Mountain Time Zone in the United States is set forth at 49 CFR 71.8.[1] The boundary between Central and Mountain time zones is set forth at 49 CFR 71.7,[2] and the boundary between Mountain and Pacific time zones is set forth at 49 CFR 71.9.[3]

ReferencesEdit

  1. ^ "49 CFR 71.8 Mountain zone". Code of Federal Regulations. Retrieved October 7, 2011.
  2. ^ "49 CFR 71.7 Boundary line between central and mountain zones". Code of Federal Regulations. Retrieved October 7, 2011.
  3. ^ "49 CFR 71.9 Boundary line between mountain and Pacific zones". Code of Federal Regulations. Retrieved October 7, 2011.
  4. ^ Robbins, Ted (March 11, 2007). "Arizona Says No to Daylight-Saving Time". Weekend Edition Sunday. National Public Radio. Retrieved June 18, 2012.