Mountain Time Zone (MT)
The Mountain Time Zone (MT) spans the Rocky Mountains and the desert Southwest, from Montana down to New Mexico and Arizona. It is the least populous of the four contiguous-US zones but covers a very large area. Its one big complication is Arizona, which stays on Mountain Standard Time all year.
| General abbreviation | MT |
|---|---|
| Standard time | MST — Mountain Standard Time, UTC−7 |
| Daylight time | MDT — Mountain Daylight Time, UTC−6 (not used in most of Arizona) |
| IANA identifiers | America/Denver (observes DST), America/Phoenix (Arizona, no DST), America/Boise (southern Idaho) |
| Military letter | T (Tango) for MST, S (Sierra) for MDT |
States in the Mountain Time Zone
Entirely on Mountain Time (6 states)
Arizona, Colorado, Montana, New Mexico, Utah, Wyoming.
Partly on Mountain Time
- Idaho — the southern part of the state, including Boise, Idaho Falls, Pocatello and Twin Falls. The northern panhandle is Pacific.
- Oregon — most of Malheur County (Ontario, Nyssa, Vale), which looks toward Boise.
- Nevada — the border city of West Wendover, which is aligned with neighbouring Wendover, Utah. A few small communities near the Idaho line, such as Jackpot, also keep Mountain Time informally.
- Texas — El Paso and Hudspeth counties.
- Kansas — Sherman, Wallace, Greeley and Hamilton counties.
- Nebraska — the western third, including the Panhandle (Scottsbluff).
- South Dakota — the western half, including Rapid City and the Black Hills.
- North Dakota — the southwestern corner, including Dickinson and Bowman.
Arizona and daylight saving time
Arizona has not observed daylight saving time since 1968, so it stays on MST (UTC−7) all year. In practice that means:
- November to March, Arizona shows the same time as Denver and the rest of the Mountain zone.
- March to November, Arizona shows the same time as California and the Pacific zone, and is one hour behind Denver.
- The Navajo Nation, which extends into northeastern Arizona, does observe daylight saving time. The Hopi Reservation, surrounded by the Navajo Nation, follows the rest of Arizona and does not.
The abbreviation for Arizona stays MST all year, even when its clock matches PDT. See the daylight saving guide for more.
Major cities on Mountain Time
Denver, Colorado Springs, Phoenix, Tucson, Mesa, Albuquerque, Santa Fe, El Paso, Salt Lake City, Provo, Boise, Billings, Missoula, Cheyenne, Casper, Rapid City and Scottsbluff.
Mountain time compared with other US zones
The table shows what time it is elsewhere when it is 12:00 PM in the Mountain zone (Denver). Differences change during daylight saving time because Arizona and Hawaii keep their clocks fixed. For any other time, use the time zone converter.
| Zone | Winter (Nov–Mar) | Difference | Summer (Mar–Nov) | Difference |
|---|---|---|---|---|
| Eastern (New York) | 2:00 PM | 2 h ahead | 2:00 PM | 2 h ahead |
| Central (Chicago) | 1:00 PM | 1 h ahead | 1:00 PM | 1 h ahead |
| Arizona (Phoenix) | 12:00 PM | same time | 11:00 AM | 1 h behind |
| Pacific (Los Angeles) | 11:00 AM | 1 h behind | 11:00 AM | 1 h behind |
| Alaska (Anchorage) | 10:00 AM | 2 h behind | 10:00 AM | 2 h behind |
| Hawaii (Honolulu) | 9:00 AM | 3 h behind | 8:00 AM | 4 h behind |
| UTC | 7:00 PM | 7 h ahead | 6:00 PM | 6 h ahead |
Right now in the other zones
Frequently asked questions
Does Arizona use Mountain Time or Pacific Time?
Arizona is in the Mountain Time Zone and uses Mountain Standard Time (UTC−7) all year. Because it skips daylight saving time, its clocks match Pacific Daylight Time from March to November and Mountain Time in winter. The Navajo Nation is the exception and does change its clocks.
What is the difference between MST and MDT?
MST (Mountain Standard Time) is UTC−7 and MDT (Mountain Daylight Time) is UTC−6. Denver, Salt Lake City and Albuquerque use MDT during daylight saving time; most of Arizona stays on MST.
Is Mountain Time 1 or 2 hours behind Eastern Time?
Mountain Time is 2 hours behind Eastern Time. Arizona is 2 hours behind Eastern in winter and 3 hours behind during daylight saving time.
Is El Paso on Mountain or Central Time?
El Paso is on Mountain Time, one hour behind Dallas, Houston and the rest of Texas.
Related guides
- Central Time Zone and Pacific Time Zone — the neighbouring zones.
- Time zone converter & chart — convert any time between US zones for any date.
- US time zones by state — every state, including the thirteen split states.
- Daylight saving time — the second-Sunday-in-March / first-Sunday-in-November rule and its exceptions.
- Time zone abbreviations — ET vs EST vs EDT, and the rest.