Convert Mountain Daylight Time to Eastern Daylight Time
Instantly convert Mountain Daylight Time (MDT) to Eastern Daylight Time (EDT) with our free online calculator.
Mountain Daylight Time
11:20:54 PM
Tue, Jun 23 (MDT)
Eastern Daylight Time
01:20:54 AM
Wed, Jun 24 (EDT)
Convert a Specific Time
24-Hour Comparison
| MDT | EDT |
|---|---|
| 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 | 12:00 AM(+1d) |
| 11:00 PM | 1:00 AM(+1d) |
How to Convert Mountain Daylight Time to Eastern Daylight Time
Formula
To convert Mountain Daylight Time (MDT) to Eastern Daylight Time (EDT): Convert MDT to EDT
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 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.