GMT to MST
-7hGMT
GMTSOURCEMST
MSTGreen rows indicate typical business hours (9 AM - 5 PM)
GMT and MST on the World Map
The map below highlights the GMT (Greenwich Mean Time) and MST (Mountain Standard Time) timezone regions across the globe.
GMT – Greenwich Mean Time
UTC+00:00Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London. It is the same as UTC+00:00.
- •GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London.
- •The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
- •GMT and UTC are often used interchangeably, but UTC is based on atomic clocks.
- •Iceland uses GMT year-round and never observes daylight saving time.
- •The UK switches from GMT to BST (British Summer Time) in late March each year.
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.
GMT vs MST: Offsets, DST and Best Call Times
GMT runs on Greenwich Mean Time (GMT) at UTC+00:00. MST runs on Mountain Standard Time (MST) at UTC-07:00. That puts GMT 7 hours behind MST — a difference of -7h at the current offsets.
In practice, when it is 9:00 AM in GMT it is 2:00 AM in MST. Midnight in GMT is 5:00 PM in MST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
GMT to MST time conversion table
| GMT (GMT) | MST (MST) | Day |
|---|---|---|
| 12:00 AM | 5:00 PM | previous day |
| 6:00 AM | 11:00 PM | previous day |
| 7:00 AM | 12:00 AM | same day |
| 8:00 AM | 1:00 AM | same day |
| 9:00 AM | 2:00 AM | same day |
| 12:00 PM | 5:00 AM | same day |
| 3:00 PM | 8:00 AM | same day |
| 5:00 PM | 10:00 AM | same day |
| 6:00 PM | 11:00 AM | same day |
| 9:00 PM | 2:00 PM | same day |
Why people convert GMT to MST time
- Scheduling a call from GMT to MST: a 10:00 AM start in GMT lands at 3:00 AM in MST, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both GMT and MST are inside the 9-to-5 working day between 4:00 PM and 5:00 PM GMT time (9:00 AM–10:00 AM MST). That is roughly 1 hours of usable overlap.
- Watching a live event or market open: GMT viewers need 2:00 AM in MST to catch a 9:00 AM start there, and 7:00 AM if the event is anchored to GMT.
- Always state the zone abbreviation, not just the hour. "3:00 PM GMT" is unambiguous; "3 PM" across a -7h gap is not.
- Block 4:00 PM–5:00 PM GMT as the recurring meeting window if you work primarily from GMT and need MST colleagues present.
About GMT (Greenwich Mean Time)
Greenwich Mean Time (GMT) is the clock time at the Royal Observatory in Greenwich, London, which sits on the Prime Meridian (0° longitude). GMT serves as the reference point from which all other time zones are calculated. The United Kingdom uses GMT during winter months and switches to British Summer Time (BST, UTC+01:00) from late March to late October. Several West African nations use GMT year-round. GMT is often used interchangeably with UTC (Coordinated Universal Time), although technically they are different – UTC is based on atomic clocks while GMT is based on Earth's rotation.
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).
Best time to call between GMT and MST
Both GMT and MST sit inside the 9 AM – 5 PM working day between 4:00 PM–5:00 PM GMT, which is 9:00 AM–10:00 AM MST. That gives roughly 1 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
GMT and MST overlap for only 60 minutes (4:00 PM–5:00 PM GMT), so meetings have to be booked precisely.
GMT is 7 hours behind MST (GMT UTC+00:00 → MST UTC-07:00). The shared working window is 4:00 PM–5:00 PM GMT. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
GMT
☀ Currently in DST
Standard: UTC+00:00 · DST: UTC+01:00
Clocks fall back on Sun, Oct 25, 2026
MST
☀ Currently in DST
Standard: UTC-07:00 · DST: UTC-06:00
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 GMT and MST?
GMT (GMT, UTC+00:00) is 7 hours behind MST (MST, UTC-07:00). The gap is currently -7h.
How do I convert GMT time to MST time?
Add -7h to GMT local time. For example, 9:00 AM in GMT is 2:00 AM in MST.
What time is it in MST right now?
MST uses MST at UTC-07:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -7h offset from GMT.
What is the best time to call MST from GMT?
Call between 4:00 PM and 5:00 PM GMT — that maps to 9:00 AM–10:00 AM MST and keeps both parties inside the working day.
Which is behind, GMT or MST?
GMT is 7 hours behind MST. When it is 12:00 PM in GMT it is 5:00 AM in MST.
Does daylight saving time affect the GMT–MST difference?
Neither zone observes daylight saving time, so the -7h offset between GMT and MST is fixed all year.
Which other cities share GMT's time zone?
GMT also covers London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar and 5 more.
Which countries use GMT, GMT's zone?
GMT is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, Mali, Mauritania and 7 more.
Is there a day difference between GMT and MST?
Not normally. The -7h gap only pushes the date over the previous day.
What is the time difference between GMT and MST?
MST is -7h from GMT.
What timezone is GMT in?
GMT operates on its local timezone.
What timezone is MST in?
MST operates on its local timezone.
Which countries use GMT (Greenwich Mean Time)?
GMT is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, and 9 more countries.
Does GMT observe daylight saving time?
Yes, GMT switches to BST during summer months.
What are some interesting facts about GMT?
GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London. The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
Which cities are in the MST timezone?
Major cities in the MST timezone include Denver, Phoenix, Salt Lake City, Calgary, Edmonton, Albuquerque, El Paso, Tucson.
What is the UTC offset for MST?
Mountain Standard Time (MST) is at UTC-07:00. During daylight saving time, it shifts to MDT.
What should I know about the MST timezone?
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.
When is it midnight in GMT, what time is it in MST?
When it is 12:00 AM (midnight) in GMT (GMT), it is -7h later in MST (MST).
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