In the United States and Canada, this time zone is generically called Mountain Time (MT). Specifically, it is Mountain Standard Time (MST) when observing standard time, and Mountain Daylight Time (MDT) when observing daylight saving time. The term refers to the Rocky Mountains, which range from British Columbia to New Mexico.

Mountain Standard Time (MST) is a standard time zone in use from the first Sunday in November to the second Sunday in March—when Daylight Saving Time (DST) is not in effect. Mountain Daylight Time (MDT) is used during the remainder of the year.

MST (Mountain Standard Time) is one of the well-known names of UTC-7 time zone which is 7h. behind of UTC (Coordinated Universal Time).The time offset from UTC can be written as -07:00. It's used during the winter. During the summer MDT - Mountain Daylight Time (UTC-6) is in use. Some locations use MST all year long.

MST stands for Mountain Standard Time. EST is known as Eastern Standard Time. EST is 2 hours ahead of MST.