MST to EST Time Converter
EST is 2 hours ahead of MST. The US Mountain states are currently on MDT (UTC-6:00), and The US East Coast is currently on EDT (UTC-4:00).
Best Time to Call Between MST and EST
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 EST. That's a 6-hour window.
both at work MST only EST only neither — hours along the strip are MST.
Common Times Converted
MST on the left, EST on the right.
MST to EST: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| MST | EST | 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 | EST only |
| 8:00 AM | 10:00 AM | EST 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 EST 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.
EST — Eastern Standard Time
New York, Toronto, Washington DC, Atlanta, Miami, Boston. Standing at UTC-5:00 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. Australia also uses EST for its own Eastern Standard Time (UTC+10), now more often written AEST.
Eastern Standard Time is only actually in force from early November to mid-March. For the other eight months the same region is on EDT, which is why so many EST conversions are quietly wrong.
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 EST
Frequently Asked Questions
What is the time difference between MST and EST?
EST is 2 hours ahead of MST.
What is 9:00 AM MST in EST?
9:00 AM MST is 11:00 AM EST.
What are the best hours to schedule a call between MST and EST?
Between 9:00 AM and 3:00 PM MST, which is 11:00 AM to 5:00 PM EST. Both sides are inside normal business hours through that window.
Does the difference between MST and EST 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.
Does EST always mean Eastern Standard Time?
Australia also uses EST for its own Eastern Standard Time (UTC+10), now more often written AEST.