What is the time difference between MST and GMT?

Greenwich Mean Time (GMT) is 6 hours ahead of Mountain Standard Time (MST). MST uses a UTC offset of UTC-6, while GMT uses UTC. For example, when it's 9:00 AM in MST, it's 3:00 PM in GMT. Note that this difference may shift by one hour during daylight saving time transitions if the two zones change on different dates. Use the conversion table above to see the exact time for each hour of the day.

How do I convert MST to GMT?

To convert MST to GMT, add 6 hours to the MST time. For example, 9:00 AM MST is 3:00 PM GMT, and 5:00 PM MST is 11:00 PM GMT. Keep in mind that during daylight saving time transitions, the offset between these timezones may temporarily change by one hour. You can also use the interactive converter above for quick, accurate results.

What time is it in GMT when it's noon in MST?

When it's 12:00 PM (noon) in MST, it's 6:00 PM in GMT. This is because GMT is 6 hours ahead of MST. Similarly, when it's 6:00 PM in MST, it's 12:00 AM in GMT. During daylight saving time transitions, these times may shift by one hour, so always verify the current offset. The color-coded conversion table above shows every hour mapped between both timezones.

How many hours ahead is GMT from MST?

GMT is 6 hours ahead of MST. This means when it's 9:00 AM in MST, it's 3:00 PM in GMT, and when it's midnight in MST, it's 6:00 AM in GMT. The exact difference can vary by one hour during daylight saving time transitions. The conversion table above provides a complete hour-by-hour mapping.

Is GMT ahead or behind MST?

GMT is ahead of MST by 6 hours. Clocks in GMT show a later time than MST, meaning the day starts earlier in GMT relative to MST. For example, when it's morning in MST, it's already afternoon or evening in GMT. This gap may change by one hour during DST transitions.

Does MST observe daylight saving time?

Yes, Mountain Standard Time observes daylight saving time. During DST, the abbreviation changes to MDT and clocks move forward by one hour, typically in spring. Clocks then fall back in autumn, returning to standard MST time. This means the UTC offset for MST shifts between two values depending on the season. Check our DST change calendar for exact transition dates that may affect your MST to GMT conversions.

Does GMT observe daylight saving time?

Yes, Greenwich Mean Time observes daylight saving time. During DST, the abbreviation changes to BST and clocks move forward by one hour, typically in spring. Clocks then fall back in autumn, returning to standard GMT time. This means the UTC offset for GMT shifts between two values depending on the season. Check our DST change calendar for exact transition dates that may affect your MST to GMT conversions.

What is the best time to call from MST to GMT?

The best time for a call between MST and GMT is during overlapping business hours (9 AM – 5 PM) in both timezones. To reach someone in GMT during their work day, call between 3:00 AM and 11:00 AM your MST time. Avoid calling too early or late, as the 6 hours difference means your evening could be their late night. Check the color-coded conversion table above — green hours indicate business hours in both zones, making it easy to find the ideal time.

When does daylight saving time change in MST?

Daylight saving time transitions vary by year and region. Mountain Standard Time observes DST, which typically shifts clocks forward by one hour in spring ("spring forward") and back in fall ("fall back"). During these transition periods, the time difference between MST and GMT may temporarily change by one hour, which can cause confusion for scheduled meetings or calls. It's important to double-check your conversions around transition dates, especially if the two timezones switch on different dates. Check our DST change calendar for exact transition dates in the current year.

Do MST and GMT ever have the same time?

No, MST and GMT are always 6 hours apart and never display the same clock time simultaneously. Both timezones observe DST and typically transition around the same period, so the standard difference remains consistent throughout the year. The 6 hours offset is determined by their fixed positions relative to the Prime Meridian (UTC). You can always rely on this consistent difference when planning across these timezones.

MST to GMT Converter

Convert Mountain Standard Time to Greenwich Mean Time. See the hour-by-hour conversion table below.

Upcoming DST Change

UK Time (BST) will fall back on October 25. Clocks will shift by 1 hour (BST → GMT).

Mountain Time (MDT) will fall back on November 1. Clocks will shift by 1 hour (MDT → MST).

View all DST changes

Timezone Details

Mountain Standard Time

7:48 PM

Saturday, October 24, 2026

MDT (UTC-06:00)

Greenwich Mean Time

1:48 AM

Sunday, October 25, 2026

GMT (UTC+00:00)

Difference: +6 hours

MDT DST: Yes (MDT)

GMT DST: Yes (BST)

24-Hour Overview

MDT — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

GMT — 24-hour overview

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

12a12a

3a3a

NightMorningBusinessEvening

Frequently Asked Questions

Related Conversions

GMT to MST EST to GMT GMT to EST PST to GMT GMT to PST GMT to IST IST to GMT GMT to CET CET to GMT

Cities in These Timezones

MST Cities

Denver

GMT Cities

London Manchester Edinburgh

More Tools

Compare MST & GMT Plan a Meeting (MST & GMT)See on Map

Learn More

How Time Zones Work Understanding DST Timezone Abbreviations

External Resources

Mountain Standard Time on Wikipedia Greenwich Mean Time on Wikipedia IANA Time Zone Database