Mountain Time (Denver)

Mountain Time (MT) covers the Rocky Mountain region of the United States and western Canada. MST (Mountain Standard Time) is UTC-7, while MDT (Mountain Daylight Time) is UTC-6 during daylight saving months. The timezone spans from the peaks of the Rockies through the high desert of the Southwest. Denver, the Mile High City, serves as the unofficial capital of the Mountain timezone. Notably, Arizona (except the Navajo Nation) does not observe daylight saving time, staying on MST year-round — a decision made in 1968 to avoid an extra hour of extreme afternoon heat. This creates scheduling complexity, as Arizona aligns with Pacific Daylight Time in summer and Mountain Standard Time in winter. The Mountain timezone is home to major military installations including NORAD in Cheyenne Mountain and several Air Force bases. Alberta and parts of British Columbia in Canada also use Mountain Time. The timezone has grown in importance as the tech industry has expanded into cities like Denver, Salt Lake City, and Boise.