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.

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

• Phoenix, Arizona - US (All Year)
• Denver, Colorado - US (Winter)
• Edmonton-CA (Winter)

The IANA time zone identifiers for Mountain Standard Time are America/Creston, America/Dawson_Creek, America/Fort_Nelson and America/Phoenix.