Convert Mountain Daylight Time to Mountain Standard Time
Instantly convert Mountain Daylight Time (MDT) to Mountain Standard Time (MST) with our free online calculator.
Mountain Daylight Time
11:20:54 PM
Tue, Jun 23 (MDT)
Mountain Standard Time
10:20:54 PM
Tue, Jun 23 (MST)
Convert a Specific Time
24-Hour Comparison
| MDT | MST |
|---|---|
| 12:00 AM | 11:00 PM(-1d) |
| 1:00 AM | 12:00 AM |
| 2:00 AM | 1:00 AM |
| 3:00 AM | 2:00 AM |
| 4:00 AM | 3:00 AM |
| 5:00 AM | 4:00 AM |
| 6:00 AM | 5:00 AM |
| 7:00 AM | 6:00 AM |
| 8:00 AM | 7:00 AM |
| 9:00 AM | 8:00 AM |
| 10:00 AM | 9:00 AM |
| 11:00 AM | 10:00 AM |
| 12:00 PM | 11:00 AM |
| 1:00 PM | 12:00 PM |
| 2:00 PM | 1:00 PM |
| 3:00 PM | 2:00 PM |
| 4:00 PM | 3:00 PM |
| 5:00 PM | 4:00 PM |
| 6:00 PM | 5:00 PM |
| 7:00 PM | 6:00 PM |
| 8:00 PM | 7:00 PM |
| 9:00 PM | 8:00 PM |
| 10:00 PM | 9:00 PM |
| 11:00 PM | 10:00 PM |
How to Convert Mountain Daylight Time to Mountain Standard Time
Formula
To convert Mountain Daylight Time (MDT) to Mountain Standard Time (MST): Convert MDT to MST
About Mountain Daylight Time (MDT)
Mountain Daylight Time (MDT, IANA: America/Denver during DST window) is the summer-time variant of MST, set at UTC-6:00 — observed from the second Sunday in March to the first Sunday in November per the Energy Policy Act of 2005. MDT shares the same UTC offset as Central Standard Time (CST), which can cause cross-time-zone scheduling confusion during the DST transition windows in March and November. The Navajo Nation in northeastern Arizona does observe MDT (unlike the rest of Arizona), creating one of the rare US sub-state time-zone exceptions per the Navajo Nation Council's 1968 resolution. MDT applies in Colorado, Utah, Wyoming, Montana, Idaho east, New Mexico, parts of Texas, and Canadian Rocky Mountain provinces (Alberta, eastern BC). Used in coordination of: Denver International Airport flight operations, ski-area lift hours during shoulder-season DST window, Yellowstone National Park ranger schedules, US National Renewable Energy Lab operations, and FAA Albuquerque ARTCC ATC operations.
About Mountain Standard Time (MST)
Mountain Standard Time (MST, IANA: America/Denver and America/Phoenix) is the time zone for the US Mountain region and most of Canada's Rocky Mountain provinces, set at UTC-7:00. MST is observed from the first Sunday in November to the second Sunday in March; the region switches to Mountain Daylight Time (MDT = UTC-6:00) for the remainder of the year — EXCEPT for the State of Arizona (excluding Navajo Nation), which stays on MST year-round per Arizona Revised Statutes §1-242. Major MST cities: Denver, Phoenix, Salt Lake City, Albuquerque, El Paso, Tucson, Calgary, Edmonton. MST covers Colorado, Utah, Wyoming, Montana, Idaho (most), New Mexico, Arizona, parts of Texas + Mexico (Sonora). Population ~17 million in the time zone. Affects: NORAD Cheyenne Mountain operations, Denver Mile-High Stadium NFL game scheduling, Colorado ski-resort lift-operating hours, US Bureau of Land Management permit operations, and the Mormon Tabernacle Choir broadcast schedule from Salt Lake City.