Current MST Time

Mountain Standard Time (MST)

MST (Mountain Standard Time) is UTC-7:00, covering states like Colorado, Utah, Montana, Wyoming, New Mexico, and parts of Idaho and Oregon. Arizona (except the Navajo Nation) stays on MST year-round and never observes MDT. The IANA timezone America/Denver covers the DST-observing mountain region.

Where Mountain Standard Time is observed

MST (UTC−7) covers the US and Canadian Mountain Time region year-round in some places and as a winter standard in others. IANA: America/Denver.

• United States: Denver, Salt Lake City, Albuquerque, El Paso, Boise
• Year-round MST (no DST): most of Arizona (America/Phoenix), Sonora in Mexico, Saskatchewan (CST equivalent)
• Canada: most of Alberta, parts of British Columbia and the Northwest Territories
• Mexico: Sonora observes MST year-round; Chihuahua and Baja California Sur observe MST in winter

MST vs MDT — and the Arizona exception

Most of Mountain Time switches to MDT (UTC−6) in summer, but Arizona stays on MST year-round — apart from the Navajo Nation, which does observe DST. A "Mountain Time" value can mean different offsets in the same state on the same date.

• MDT = UTC−6; MST = UTC−7
• America/Phoenix is the IANA name for permanent-MST Arizona
• Navajo Nation uses America/Denver and observes DST
• British Columbia’s Peace River District also stays on MST year-round

MST and Unix epoch — conversion examples

Mountain Standard Time is UTC−7. Converting a wall-clock MST time to Unix epoch means adding seven hours to get UTC. For example, 2026-01-15 08:00:00 MST corresponds to 2026-01-15 15:00:00 UTC, which is 1768570800 seconds since the epoch. Outside Arizona, the zone flips to MDT (UTC−6) during US summer months, so most date libraries report 'America/Denver' as MST in winter and MDT in summer.

• MST epoch = UTC epoch + 25200 (UTC − 7 = MST)
• Arizona stays on MST year-round (IANA zone 'America/Phoenix')
• Most of the Mountain timezone uses 'America/Denver' which switches to MDT in summer
• Python: datetime(2026,1,15,8,tzinfo=ZoneInfo('America/Denver')).timestamp() → 1768570800.0

MST in scheduled jobs and reporting

Teams that run cron jobs against MST need to decide whether the schedule should follow the wall clock or the absolute UTC instant. Following the wall clock keeps a 09:00 MST job running at 09:00 local time year-round, which means the underlying UTC time shifts by one hour at each DST transition for non-Arizona regions. Following UTC keeps the absolute schedule stable but means the local clock shifts twice a year. Pick one and write it down.

• For Arizona-only reporting, use 'America/Phoenix' — no DST transitions to break SUM/AVG windows
• For multi-state Mountain region, use 'America/Denver' and write DST handling into the cron operator
• Avoid fixed '−7' offsets in code — they go wrong half the year for non-Arizona zones
• Document whether end-of-day rollups close at MST midnight or UTC midnight