EST to MST converter
Mountain Time is 2 hours behind Eastern Time year-round: Eastern Time runs at UTC−5 / UTC−4 and Mountain Time at UTC−7 / UTC−6. To convert EST to MST, subtract 2 hours from the EST time. Both zones shift by an hour on the same dates, so the gap never moves.
Eastern Time runs at UTC−5 / UTC−4, Mountain Time at UTC−7 / UTC−6.
EST to MST conversion table
Every hour of the day converted. One column is enough here: the gap between the two zones is the same in winter and summer.
| Eastern Time (EST / EDT) | Mountain Time (MST / MDT) |
|---|---|
| 00:00 12:00 AM | 22:00 10:00 PM previous day |
| 01:00 1:00 AM | 23:00 11:00 PM previous day |
| 02:00 2:00 AM | 00:00 12:00 AM |
| 03:00 3:00 AM | 01:00 1:00 AM |
| 04:00 4:00 AM | 02:00 2:00 AM |
| 05:00 5:00 AM | 03:00 3:00 AM |
| 06:00 6:00 AM | 04:00 4:00 AM |
| 07:00 7:00 AM | 05:00 5:00 AM |
| 08:00 8:00 AM | 06:00 6:00 AM |
| 09:00 9:00 AM | 07:00 7:00 AM |
| 10:00 10:00 AM | 08:00 8:00 AM |
| 11:00 11:00 AM | 09:00 9:00 AM |
| 12:00 12:00 PM | 10:00 10:00 AM |
| 13:00 1:00 PM | 11:00 11:00 AM |
| 14:00 2:00 PM | 12:00 12:00 PM |
| 15:00 3:00 PM | 13:00 1:00 PM |
| 16:00 4:00 PM | 14:00 2:00 PM |
| 17:00 5:00 PM | 15:00 3:00 PM |
| 18:00 6:00 PM | 16:00 4:00 PM |
| 19:00 7:00 PM | 17:00 5:00 PM |
| 20:00 8:00 PM | 18:00 6:00 PM |
| 21:00 9:00 PM | 19:00 7:00 PM |
| 22:00 10:00 PM | 20:00 8:00 PM |
| 23:00 11:00 PM | 21:00 9:00 PM |
How the EST to MST conversion works
Converting EST to MST means taking a wall-clock time in Eastern Time (EST / EDT, UTC−5 / UTC−4) and expressing the same instant in Mountain Time (MST / MDT, UTC−7 / UTC−6). The arithmetic is one step: subtract 2 hours from any EST time, and it holds on every date of the year. Applying the gap pushes part of the day onto a different calendar date — the table below marks every row that shifts. In code, store the instant in UTC and convert with the IANA identifiers America/New_York and America/Denver, never with the abbreviations. One note on the source label: EST is also used for Australian Eastern Standard Time (UTC+10), so the abbreviation alone is ambiguous. On the target label: MST covers America/Denver, which shifts to MDT in summer, and America/Phoenix, which does not shift at all. A bare "09:00" carries no offset and means nothing until you attach the zone it belongs to.
Best time for meetings between EST and MST
Working hours are taken as 09:00–18:00 in each zone. The window in force depends on the date, so both halves of the year are listed where they differ.
MST / MDT, year-round
A 9-to-6 working day in both zones overlaps for 7 hours: 11:00 AM–6:00 PM EST is 9:00 AM–4:00 PM MST. Book inside that window and neither side is working outside normal hours.
Daylight saving time: which side moves
Both Eastern Time and Mountain Time shift their clocks on the same dates, by the same hour, in the same direction. The gap between them therefore holds at 2 hours on every date, including the two transition weekends.
US daylight saving time runs from the second Sunday in March to the first Sunday in November. Arizona is the exception: most of the state stays on MST year-round and never shifts to MDT.
- Eastern Time
- America/New_York
- EST / EDT — UTC−5 / UTC−4
- Mountain Time
- America/Denver
- MST / MDT — UTC−7 / UTC−6
Frequently asked questions
What is the time difference between EST and MST?
Mountain Time runs 2 hours behind Eastern Time on every date of the year. In offset terms, Eastern Time sits at UTC−5 / UTC−4 and Mountain Time at UTC−7 / UTC−6. So 9:00 AM EST is 7:00 AM MST. The hour-by-hour table on this page lists the conversion for all 24 hours so you do not have to do the arithmetic.
Does the EST to MST difference change with daylight saving time?
The difference holds at 2 hours on every date. Both Eastern Time and Mountain Time shift by an hour on the same dates and in the same direction, so the gap between them never moves, not even across a transition weekend. In the US that means clocks move forward on the second Sunday of March and back on the first Sunday of November.
What time is 9 am EST in MST?
9:00 AM EST is 7:00 AM in Mountain Time, and it stays that way all year because the two zones stay 2 hours apart. The rule is the same one the whole page runs on: subtract 2 hours from any EST time. Check the hour-by-hour table for any other starting hour, including the rows that land on the previous or next calendar day.
What do EST and MST stand for?
EST stands for Eastern Standard Time, and EDT is Eastern Daylight Time. MST stands for Mountain Standard Time, and MDT is Mountain Daylight Time. Both are display labels rather than rules: the offsets behind them come from the IANA identifiers America/New_York and America/Denver. EST is also used for Australian Eastern Standard Time (UTC+10), so the abbreviation alone is ambiguous.
Related conversions
Need more than two zones at once? The full timezone converter shows a single moment across up to six IANA timezones, for any date you choose.