MST to EDT Time Converter
EDT is 2 hours ahead of MST. The US Mountain states are currently on MDT (UTC-6:00), and EDT is UTC-4:00.
Best Time to Call Between MST and EDT
Both zones are inside normal business hours between 9:00 AM and 3:00 PM MST — that's 11:00 AM to 5:00 PM EDT. That's a 6-hour window.
both at work MST only EDT only neither — hours along the strip are MST.
Common Times Converted
MST on the left, EDT on the right.
MST to EDT: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| MST | EDT | Working hours |
|---|---|---|
| 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 | EDT only |
| 8:00 AM | 10:00 AM | EDT only |
| 9:00 AM | 11:00 AM | Both zones |
| 10:00 AM | 12:00 PM | Both zones |
| 11:00 AM | 1:00 PM | Both zones |
| 12:00 PM | 2:00 PM | Both zones |
| 1:00 PM | 3:00 PM | Both zones |
| 2:00 PM | 4:00 PM | Both zones |
| 3:00 PM | 5:00 PM | MST only |
| 4:00 PM | 6:00 PM | MST only |
| 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 next day | — |
| 11:00 PM | 1:00 AM next day | — |
What MST and EDT Actually Are
MST — Mountain Standard Time
Denver, Salt Lake City, Calgary — and Phoenix year-round. Standing at UTC-7:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, November 1, 2026, to MST. Arizona stays on MST all year, so Phoenix and Denver are an hour apart for eight months and identical for four.
Arizona has stayed on MST year-round since 1968 — the Navajo Nation within it does observe daylight saving, making the state a patchwork.
EDT — Eastern Daylight Time
New York, Toronto, Washington DC, Atlanta, Miami, Boston. Standing at UTC-4:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, November 1, 2026, to EST.
EDT runs from the second Sunday in March to the first Sunday in November — about eight months, making the "daylight" version the majority of the year rather than the exception.
What This Means in Practice
Both sides change clocks, on different dates
Both regions observe daylight saving but do not switch on the same day, so for a week or two each spring and fall the gap between them is an hour different from the rest of the year. Those short windows are where recurring invitations quietly break.
Close enough to share a working day
At only 2 hours apart, the two working days overlap almost completely. Scheduling is barely constrained by the difference.
Major Cities in Each Zone
Cities on MST
Cities on EDT
Frequently Asked Questions
What is the time difference between MST and EDT?
EDT is 2 hours ahead of MST. That is the live figure. Taken strictly as written, the gap between MST and EDT is 3 hours — the two differ because at least one of these regions is currently on daylight saving.
What is 9:00 AM MST in EDT?
9:00 AM MST is 11:00 AM EDT.
What are the best hours to schedule a call between MST and EDT?
Between 9:00 AM and 3:00 PM MST, which is 11:00 AM to 5:00 PM EDT. Both sides are inside normal business hours through that window.
Does the difference between MST and EDT change during the year?
Yes. Both regions observe daylight saving, and they do not switch on the same dates, so the gap shifts by an hour at least twice a year. The next clock change is on Sunday, November 1, 2026.
Does MST always mean Mountain Standard Time?
Arizona stays on MST all year, so Phoenix and Denver are an hour apart for eight months and identical for four.