Mountain Time Zone

The Mountain Time Zone stretches across the Rocky Mountain states of the western United States. It runs at UTC−7 during standard time (MST) and UTC−6 during Daylight Saving Time (MDT). Notably, Arizona (with the exception of the Navajo Nation) does not observe DST and stays at MST year-round. Major cities include Denver, Phoenix, Salt Lake City, Albuquerque, Tucson, Colorado Springs, and Boise.