Convert Eastern Daylight Time to Mountain Standard Time
Instantly convert Eastern Daylight Time (EDT) to Mountain Standard Time (MST) with our free online calculator.
Eastern Daylight Time
01:20:58 AM
Wed, Jun 24 (EDT)
Mountain Standard Time
10:20:58 PM
Tue, Jun 23 (MST)
Convert a Specific Time
24-Hour Comparison
| EDT | MST |
|---|---|
| 12:00 AM | 9:00 PM(-1d) |
| 1:00 AM | 10:00 PM(-1d) |
| 2:00 AM | 11:00 PM(-1d) |
| 3:00 AM | 12:00 AM |
| 4:00 AM | 1:00 AM |
| 5:00 AM | 2:00 AM |
| 6:00 AM | 3:00 AM |
| 7:00 AM | 4:00 AM |
| 8:00 AM | 5:00 AM |
| 9:00 AM | 6:00 AM |
| 10:00 AM | 7:00 AM |
| 11:00 AM | 8:00 AM |
| 12:00 PM | 9:00 AM |
| 1:00 PM | 10:00 AM |
| 2:00 PM | 11:00 AM |
| 3:00 PM | 12:00 PM |
| 4:00 PM | 1:00 PM |
| 5:00 PM | 2:00 PM |
| 6:00 PM | 3:00 PM |
| 7:00 PM | 4:00 PM |
| 8:00 PM | 5:00 PM |
| 9:00 PM | 6:00 PM |
| 10:00 PM | 7:00 PM |
| 11:00 PM | 8:00 PM |
How to Convert Eastern Daylight Time to Mountain Standard Time
Formula
To convert Eastern Daylight Time (EDT) to Mountain Standard Time (MST): Convert EDT to MST
About Eastern Daylight Time (EDT)
Eastern Daylight Time (EDT, IANA: America/New_York during DST window) is the summer-time variant of EST, set at UTC-4:00 — observed from the second Sunday in March to the first Sunday in November per the US Energy Policy Act of 2005. EDT shares the same UTC offset as Atlantic Standard Time (AST — observed year-round in Canadian Maritimes Nova Scotia/New Brunswick/PEI and in Caribbean Puerto Rico/USVI/Bermuda) and as Bolivia/Chile/Paraguay Standard Time. The 'spring forward' transition at 02:00 EDT in March is the largest single coordinated time change in human history, affecting ~150 million US East Coast residents simultaneously per US Census. Florida passed the Sunshine Protection Act in 2018 attempting to stay on EDT year-round, but it required US Congressional approval (US Code 15 §260a) which has not been granted as of 2024. EDT affects: US Federal Government tax-filing deadlines (IRS Form 1040 due 23:59 EDT on April 15), NFL Sunday Night Football scheduling, and US Supreme Court oral-argument schedules in DC.
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.