Mountain Daylight Time is six hours behind the Coordinated Universal Time standard, written as an offset of UTC - 6:00. That means to find the standard time in the zone you must subtract six hours from Coordinated Universal Time.
Territories observing the time zone are primarily in North America. It runs through several U.S. states, including Arizona, Colorado, Kansas, Montana, New Mexico, Texas, and many more. It also passes through Canada in the North, and Mexico in the South.
Depending on where the time zone is being referenced, it may be called one of these additional names:
Mountain Daylight Saving Time or MDST
North American Mountain Daylight Time or NAMDT
Heure Avancée des Rocheuses or HAR (in French)
In many of the areas where this time zone is used, during fall to winter months Mountain Standard Time (MST) is observed, and then during Daylight Saving (spring to summer months) Mountain Daylight Time or MDT is used.