MST/MDT Mountain Time Zone

Standard time and daylight time is observed by this time zone; MST Mountain Standard Time is 7 hours behind of UTC/GMT time and MDT Mountain Daylight Time is behind by 6 hours.

Mountain Daylight Time:
Friday May 17th 6:09pm MDT
Status: Time Zone: UTC/GMT Offset:
Being Observed
MDT -06:00
Mountain Standard Time:
Friday May 17th 5:09pm MST
Status: Time Zone: UTC/GMT Offset:
Not Being Observed MST -07:00
Year: MDT Begins: MDT Ends:
2026 Sunday March 8th Sunday November 1st
2025 Sunday March 9th Sunday November 2nd
2024 Sunday March 10th Sunday November 3rd
2023 Sunday March 12th Sunday November 5th
2022 Sunday March 13th Sunday November 6th

Countries which observe the MST/MDT time zone:


  • Canada*
  • Mexico*
  • United States*

(*) indicates that the time zone is only observed in certain areas of the country. No asterisk indicates that the entire country observes this time zone.

Areas in Canada which observe the Mountain Time Zone

  • Alberta
  • British Columbia (eastern area)
  • Northwest Territories (except Tungsten)
  • Bathurst Inlet, Cambridge Bay and Umingmaktok, of Nunavut
  • Lloydminster

Parts of British Columbia (Peace River Regional District (except Fort Ware), Dawson Creek and Creston) only observe MST. All other areas observe MST as well as MDT.

Areas in the US which observe the Mountain Time Zone

  • Arizona
  • Colorado
  • Idaho (southern areas)
  • Kansas (counties bordering Colorado Greeley, Hamilton, Sherman and Wallace)
  • Montana
  • Nebraska (western third)
  • Nevada (West Wendover)
  • New Mexico
  • North Dakota (south west)
  • Oregon (majority of Malheur county)
  • South Dakota (western half)
  • Texas (El Paso and Hudspeth counties)
  • Utah
  • Wyoming

Arizona only observes MST except for the Native American-governed territory Navajo Nation which observes MST and MDT.

States in Mexico which observe the Mountain Time Zone

  • Baja California Sur
  • Chihuahua
  • Nayarit
  • Sonora
  • Sinaloa

Bay of Flags or Bahía de Banderas of Nayarit observes the central time zone. Sonora only observes MST.

« List of World Time Zones