ET to MST Time Converter
MST is 2 hours behind ET. The US East Coast is currently on EDT (UTC-4:00), and The US Mountain states are currently on MDT (UTC-6:00).
Best Time to Call Between ET and MST
Both zones are inside normal business hours between 11:00 AM and 5:00 PM ET — that's 9:00 AM to 3:00 PM MST. That's a 6-hour window.
both at work ET only MST only neither — hours along the strip are ET.
Common Times Converted
ET on the left, MST on the right.
ET to MST: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| ET | MST | Working hours |
|---|---|---|
| 12:00 AM | 10:00 PM prev day | — |
| 1:00 AM | 11:00 PM prev day | — |
| 2:00 AM | 12:00 AM | — |
| 3:00 AM | 1:00 AM | — |
| 4:00 AM | 2:00 AM | — |
| 5:00 AM | 3:00 AM | — |
| 6:00 AM | 4:00 AM | — |
| 7:00 AM | 5:00 AM | — |
| 8:00 AM | 6:00 AM | — |
| 9:00 AM | 7:00 AM | ET only |
| 10:00 AM | 8:00 AM | ET only |
| 11:00 AM | 9:00 AM | Both zones |
| 12:00 PM | 10:00 AM | Both zones |
| 1:00 PM | 11:00 AM | Both zones |
| 2:00 PM | 12:00 PM | Both zones |
| 3:00 PM | 1:00 PM | Both zones |
| 4:00 PM | 2:00 PM | Both zones |
| 5:00 PM | 3:00 PM | MST only |
| 6:00 PM | 4:00 PM | MST only |
| 7:00 PM | 5:00 PM | — |
| 8:00 PM | 6:00 PM | — |
| 9:00 PM | 7:00 PM | — |
| 10:00 PM | 8:00 PM | — |
| 11:00 PM | 9:00 PM | — |
What ET and MST Actually Are
ET — Eastern 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.
Eastern Time covers roughly half the US population and, because of that, is the zone most American business defaults to when nobody specifies one.
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.
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 ET
Cities on MST
Frequently Asked Questions
What is the time difference between ET and MST?
MST is 2 hours behind ET.
What is 9:00 AM ET in MST?
9:00 AM ET is 7:00 AM MST.
What are the best hours to schedule a call between ET and MST?
Between 11:00 AM and 5:00 PM ET, which is 9:00 AM to 3:00 PM MST. Both sides are inside normal business hours through that window.
Does the difference between ET and MST 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.