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)

The IANA time zone identifiers for Mountain Time are America/Boise and America/Denver.

Where is Mountain Time observed?

States in the US that use MDT and MST:

• Arizona - (Navajo Nation)
• Colorado
• Idaho (parts)
• Kansas (parts)
• Montana
• Nebraska (parts)
• New Mexico
• North Dakota (parts)
• Oregon (parts)
• South Dakota (parts)
• Texas (parts)
• Utah
• Wyoming

US Cities on Mountain Time Zone

Follow DST

• Denver (Colorado)
• El Paso (Texas)
• Boise (Idaho)
• Salt Lake City (Utah)

Doesn't follow DST

• Phoenix (Arizona)

Related: US Timezones.