MST to EDT
+3hMST
MSTSOURCEEDT
EDTGreen rows indicate typical business hours (9 AM - 5 PM)
MST and EDT on the World Map
The map below highlights the MST (Mountain Standard Time) and EDT (Eastern Daylight Time) timezone regions across the globe.
MST – Mountain Standard Time
UTC-07:00Mountain Standard Time (MST) is the time zone for the Mountain region of North America, 7 hours behind UTC.
- •Arizona does not observe daylight saving time, staying on MST year-round.
- •The Navajo Nation in Arizona does observe DST, unlike the rest of the state.
- •Denver, the 'Mile High City', is the largest city fully in MST.
- •MST covers 6 US states entirely and parts of several others.
EDT – Eastern Daylight Time
UTC-04:00Eastern Daylight Time (EDT) is the daylight saving time observed in the Eastern Time Zone, 4 hours behind UTC.
- •EDT is observed from the second Sunday of March to the first Sunday of November.
- •During EDT, the US East Coast is only 4 hours behind London (instead of 5).
- •Not all EST locations switch to EDT – Panama and Jamaica stay on EST year-round.
Comparing Time Zones: MST and EDT
MST runs on Mountain Standard Time (MST) at UTC-07:00. EDT runs on Eastern Daylight Time (EDT) at UTC-04:00. That puts MST 3 hours ahead of EDT — a difference of +3h at the current offsets.
In practice, when it is 9:00 AM in MST it is 12:00 PM in EDT. Midnight in MST is 3:00 AM in EDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
MST to EDT time conversion table
| MST (MST) | EDT (EDT) | Day |
|---|---|---|
| 12:00 AM | 3:00 AM | same day |
| 6:00 AM | 9:00 AM | same day |
| 7:00 AM | 10:00 AM | same day |
| 8:00 AM | 11:00 AM | same day |
| 9:00 AM | 12:00 PM | same day |
| 12:00 PM | 3:00 PM | same day |
| 3:00 PM | 6:00 PM | same day |
| 5:00 PM | 8:00 PM | same day |
| 6:00 PM | 9:00 PM | same day |
| 9:00 PM | 12:00 AM | next day |
Why people convert MST to EDT time
- Scheduling a call from MST to EDT: a 10:00 AM start in MST lands at 1:00 PM in EDT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both MST and EDT are inside the 9-to-5 working day between 9:00 AM and 2:00 PM MST time (12:00 PM–5:00 PM EDT). That is roughly 5 hours of usable overlap.
- Booking travel or deliveries: tracking EDT local time against MST keeps pickup windows and arrival estimates honest across the +3h offset.
- Always state the zone abbreviation, not just the hour. "3:00 PM MST" is unambiguous; "3 PM" across a +3h gap is not.
- Block 9:00 AM–2:00 PM MST as the recurring meeting window if you work primarily from MST and need EDT colleagues present.
About MST (Mountain Standard Time)
Mountain Standard Time (MST) covers the Rocky Mountain region of the United States and Canada. Arizona is notable for not observing daylight saving time, staying on MST year-round (except the Navajo Nation). The time zone includes major cities like Denver, Phoenix, Calgary, and Salt Lake City. During summer, most areas switch to Mountain Daylight Time (MDT, UTC-06:00).
About EDT (Eastern Daylight Time)
Eastern Daylight Time (EDT) is used during the summer months (second Sunday of March to the first Sunday of November) in the Eastern Time Zone. During EDT, clocks are advanced by one hour to take advantage of longer daylight hours. Not all locations in the Eastern Time Zone observe DST – Panama, Jamaica, and most of the Caribbean remain on EST year-round.
Best time to call between MST and EDT
Both MST and EDT sit inside the 9 AM – 5 PM working day between 9:00 AM–2:00 PM MST, which is 12:00 PM–5:00 PM EDT. That gives roughly 5 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
MST and EDT share 5 hours of working-hours overlap (9:00 AM–2:00 PM MST), so scheduling a live meeting is straightforward.
MST is 3 hours ahead of EDT (MST UTC-07:00 → EDT UTC-04:00). The shared working window is 9:00 AM–2:00 PM MST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
MST
☀ Currently in DST
Standard: UTC-07:00 · DST: UTC-06:00
Clocks fall back on Sun, Nov 1, 2026
EDT
☀ Currently in DST
Standard: UTC-05:00 · DST: UTC-04:00
Clocks fall back on Sun, Nov 1, 2026
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between MST and EDT?
MST (MST, UTC-07:00) is 3 hours ahead of EDT (EDT, UTC-04:00). The gap is currently +3h.
How do I convert MST time to EDT time?
Add +3h to MST local time. For example, 9:00 AM in MST is 12:00 PM in EDT.
What time is it in EDT right now?
EDT uses EDT at UTC-04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +3h offset from MST.
What is the best time to call EDT from MST?
Call between 9:00 AM and 2:00 PM MST — that maps to 12:00 PM–5:00 PM EDT and keeps both parties inside the working day.
Which is ahead, MST or EDT?
MST is 3 hours ahead of EDT. When it is 12:00 PM in MST it is 3:00 PM in EDT.
Does daylight saving time affect the MST–EDT difference?
Neither zone observes daylight saving time, so the +3h offset between MST and EDT is fixed all year.
Which other cities share MST's time zone?
MST also covers Denver, Phoenix, Salt Lake City, Calgary, Edmonton, Albuquerque, El Paso, Tucson and 2 more.
Which countries use MST, MST's zone?
MST is used in United States (Mountain), Canada (Alberta), Mexico (Chihuahua, Sonora).
Is there a day difference between MST and EDT?
Not normally. The +3h gap only pushes the date over for late-evening times.
What is the time difference between MST and EDT?
EDT is +3h from MST.
What timezone is MST in?
MST operates on its local timezone.
What timezone is EDT in?
EDT operates on its local timezone.
Which countries use MST (Mountain Standard Time)?
MST is used in United States (Mountain), Canada (Alberta), Mexico (Chihuahua, Sonora).
Does MST observe daylight saving time?
Yes, MST switches to MDT during summer months.
What are some interesting facts about MST?
Arizona does not observe daylight saving time, staying on MST year-round. The Navajo Nation in Arizona does observe DST, unlike the rest of the state.
Which cities are in the EDT timezone?
Major cities in the EDT timezone include New York City, Washington D.C., Toronto, Miami, Philadelphia, Atlanta, Boston, Montreal.
What is the UTC offset for EDT?
Eastern Daylight Time (EDT) is at UTC-04:00. During daylight saving time, it shifts to EST.
What should I know about the EDT timezone?
EDT is observed from the second Sunday of March to the first Sunday of November. During EDT, the US East Coast is only 4 hours behind London (instead of 5).
When is it midnight in MST, what time is it in EDT?
When it is 12:00 AM (midnight) in MST (MST), it is +3h later in EDT (EDT).
Related Developer Tools
Explore more tools that work great with timezone conversions for international teams:
Related Timezone Conversions
More MST time conversions
- mst to denver
- mst to mdt
- mst to new york
- mst to london
- mst to dubai
- mst to tokyo
- mst to singapore
- mst to sydney
- mst to los angeles
- mst to paris
- mst to delhi
- mst to mumbai
- mst to berlin
- mst to hong kong
- mst to toronto
- mst to kathmandu
- new york to mst
- london to mst
- dubai to mst
- tokyo to mst
- singapore to mst
- sydney to mst
- los angeles to mst
- paris to mst
- delhi to mst
- mumbai to mst
- berlin to mst
- hong kong to mst
- toronto to mst
- kathmandu to mst
See every conversion from MST →·See every conversion from EDT →