MST — Mountain Standard Time

UTC-7 · US Mountain Region · Arizona observes MST year-round

MT — Mountain Standard Time
--:--:--
MST UTC-7MDT UTC-6 (DST)

Time Zone Facts

Standard Offset
UTC-7
DST Offset
UTC-6
Standard Abbr
MST
DST Abbr
MDT
IANA Identifier
America/Denver
DST Schedule
2nd Sunday in March → 1st Sunday in November (except Arizona)

States in MT — Mountain Time

ColoradoMontanaNew MexicoUtahWyomingArizona (year-round MST, no DST)Idaho (south)Kansas (west)Nebraska (west)Nevada (east)North Dakota (west)South Dakota (west)Texas (west)

Major Cities in MT

DenverPhoenixSalt Lake CityAlbuquerqueTucsonEl PasoCalgaryBoise

Daylight Saving Time

Observes DST: 2nd Sunday in March → 1st Sunday in November (except Arizona)

Clocks spring forward 1 hour at 2:00 AM on the second Sunday in March, changing from MST (UTC-7) to MDT (UTC-6).

Clocks fall back 1 hour at 2:00 AM on the first Sunday in November, returning from MDT (UTC-6) to MST (UTC-7).

Frequently Asked Questions

What is MST?
MST stands for Mountain Standard Time. It is UTC-7, meaning 7 hours behind Coordinated Universal Time. MST is used by the US Mountain region during winter (from the first Sunday in November to the second Sunday in March). During summer, most of the zone observes MDT (Mountain Daylight Time, UTC-6). Exception: Arizona observes MST year-round and does not change clocks.
Does Arizona observe Daylight Saving Time?
No. Arizona (except the Navajo Nation) does not observe Daylight Saving Time and stays on MST (UTC-7) year-round. This means Arizona is the same as PDT in summer but the same as MST/MDT in winter. When the rest of the Mountain zone moves to MDT (UTC-6), Arizona remains at UTC-7.
What is the difference between MST and MDT?
MST (Mountain Standard Time) is UTC-7, active from the first Sunday in November to the second Sunday in March. MDT (Mountain Daylight Time) is UTC-6, active during Daylight Saving Time from the second Sunday in March to the first Sunday in November. Arizona does not switch to MDT and stays on MST all year.
What cities are in MST / Mountain Time?
Major cities in Mountain Time include Denver, Phoenix (year-round MST), Salt Lake City, Albuquerque, Tucson, El Paso, Boise, and Calgary (Canada). Note: Denver observes MST in winter and MDT in summer, while Phoenix stays on MST all year.
How does MST compare to EST, CST, and PST?
MST (UTC-7) is 2 hours behind EST (UTC-5), 1 hour behind CST (UTC-6), and 1 hour ahead of PST (UTC-8). When it is 12:00 PM EST in New York, it is 10:00 AM MST in Denver and 9:00 AM PST in Los Angeles. These relationships hold consistently because all zones observe DST simultaneously (except Arizona).

MST Converters & Related Time Zones

Mountain Time Zone GuideEST — Eastern Standard TimePST — Pacific Standard TimeCST — Central Standard TimeMST to ESTMST to PSTMST to GMTMST to CSTUS Time Zone MapDaylight Saving TimeArizona Time Zone
MST data sourced from IANA Time Zone Database (America/Denver for DST zones, America/Phoenix for Arizona). UTC-7 in standard time, UTC-6 during Daylight Saving Time (except Arizona which stays UTC-7 year-round).