ESTtoMSTEastern Standard Time to Mountain Standard Time
EST
Eastern Standard Time (EDT)MST
Mountain Standard Time (MDT)Mutual Working Window: 6 Overlapping Hours
Recommended calling window between EST and MST
Both locations share 6 overlapping standard business hours (9:00 AM – 5:00 PM). This is the premier window for real-time video conferences, corporate calls, and instant collaboration without outside-hours disruption.
24-Hour Schedule Conversion Matrix
Compare every hour of the day between EST and MST.
| EST Time (Eastern Standard Time) | MST Time (Mountain Standard Time) | Status & Recommendation |
|---|---|---|
| 00:00AM | 22:00PM-1 day | ⚪ Outside Work Hours |
| 01:00AM | 23:00PM-1 day | ⚪ Outside Work Hours |
| 02:00AM | 00:00AM | ⚪ Outside Work Hours |
| 03:00AM | 01:00AM | ⚪ Outside Work Hours |
| 04:00AM | 02:00AM | ⚪ Outside Work Hours |
| 05:00AM | 03:00AM | ⚪ Outside Work Hours |
| 06:00AM | 04:00AM | ⚪ Outside Work Hours |
| 07:00AM | 05:00AM | ⚪ Outside Work Hours |
| 08:00AM | 06:00AM | ⚪ Outside Work Hours |
| 09:00AM | 07:00AM | 🟡 Feasible (Shoulder Hour) |
| 10:00AM | 08:00AM | 🟡 Feasible (Shoulder Hour) |
| 11:00AM | 09:00AM | 🟢 Ideal Meeting Window |
| 12:00PM | 10:00AM | 🟢 Ideal Meeting Window |
| 13:00PM | 11:00AM | 🟢 Ideal Meeting Window |
| 14:00PM | 12:00PM | 🟢 Ideal Meeting Window |
| 15:00PM | 13:00PM | 🟢 Ideal Meeting Window |
| 16:00PM | 14:00PM | 🟢 Ideal Meeting Window |
| 17:00PM | 15:00PM | ⚪ Outside Work Hours |
| 18:00PM | 16:00PM | ⚪ Outside Work Hours |
| 19:00PM | 17:00PM | ⚪ Outside Work Hours |
| 20:00PM | 18:00PM | ⚪ Outside Work Hours |
| 21:00PM | 19:00PM | ⚪ Outside Work Hours |
| 22:00PM | 20:00PM | ⚪ Outside Work Hours |
| 23:00PM | 21:00PM | ⚪ Outside Work Hours |
Frequently Asked Questions
What is the time difference between EST and MST?
MST is 2 hours behind EST. When it is 12:00 PM (noon) in EST, the current synchronized time in MST is 10:00 AM.
What are the overlapping working hours between EST and MST?
There are 6 overlapping standard business hours (9:00 AM – 5:00 PM) between EST and MST. The optimal scheduling window is 11:00 AM – 5:00 PM in EST (9:00 AM – 3:00 PM in MST).
Does daylight saving time affect the conversion between EST and MST?
Yes. Both EST and MST observe seasonal daylight saving time shifts.
What regions and major cities observe EST and MST?
EST (Eastern Standard Time) is primarily observed across Eastern North America (US East Coast & Eastern Canada) (key hubs include New York, Toronto, Miami, Atlanta). MST (Mountain Standard Time) is observed across Mountain Region North America (Colorado, Arizona, Utah, Alberta) (key hubs include Denver, Phoenix, Salt Lake City, Calgary).
What is 9:00 AM EST in MST?
9:00 AM in EST corresponds to 7:00 AM in MST. You can cross-reference every hour of the day in the 24-hour visual schedule table above.
Which time zone is ahead, EST or MST?
EST is ahead by 2 hours.