Mountain Time Zone

n. Mountain time, time zone west of Greenwich (used in the mountain states of USA) which subtracts 7 hours from UTC during standard time and 6 hours during daylight saving time

The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time (UTC-7) during the shortest days of autumn and winter, and by subtracting six hours during daylight saving time in the spring, summer, and early autumn (UTC-6). The clock time in this zone is based on the mean solar time of the 105th degree meridian west of the Greenwich Observatory.
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