Daylight Saving Time

• Mountain Daylight Saving Time (MDT) starts on the second Sunday of March (The clock went forward by one hour).
• MDT ends on the first Sunday of November (The clock time will go back one hour).
• Mountain Standard Time (MST) is used during the remainder of the year.

• Mountain Time:
  • MST - Mountain Standard Time (UTC-7)
  • MDT - Mountain Daylight Time (UTC-6)

Helena, Billings, Bozeman, Butte, Eureka, Greag Falls, Hamilton, Missoula, Polson, Sidney, West Yellowstone.

The IANA time zone identifiers for Montana is America/Denver.

Related: US Timezones, when does the time change.