GMT to MST Converter
Convert time between Greenwich Mean Time (GMT) and Mountain Standard Time (MST)
Greenwich Mean Time (GMT)
Mountain Standard Time (MST)
Time Difference
Mountain Standard Time (MST) is 0 hours ahead of Greenwich Mean Time (GMT)
Select Date
Select Time
Quick Reference
| GMT | MST |
|---|---|
| 02:00 | 19:00 |
| 04:00 | 21:00 |
| 06:00 | 23:00 |
| 08:00 | 01:00 |
| 10:00 | 03:00 |
| 12:00 | 05:00 |
| 14:00 | 07:00 |
| 16:00 | 09:00 |
| 18:00 | 11:00 |
| 20:00 | 13:00 |
| 22:00 | 15:00 |
| 00:00 | 17:00 |
Top 10 Most Common Time Zones
| Abbreviation | Full Name | UTC Offset | Typical Use |
|---|---|---|---|
| UTC | Coordinated Universal Time | UTC ±0 | Global reference standard (servers, logs, APIs) |
| EST / EDT | Eastern (US) Time | UTC −5 / −4 | New York, Toronto — North American business hub |
| CST / CDT | Central (US) Time | UTC −6 / −5 | Chicago, Dallas — US central business region |
| PST / PDT | Pacific (US) Time | UTC −8 / −7 | San Francisco, Los Angeles — tech industry standard |
| GMT / BST | Greenwich Mean / British Summer Time | UTC 0 / +1 | UK, used globally as a reference with UTC |
| CET / CEST | Central European (Summer) Time | UTC +1 / +2 | Paris, Berlin, Amsterdam — EU business core |
| IST | India Standard Time | UTC +5:30 | India — major IT & outsourcing region |
| CST | China Standard Time | UTC +8 | Beijing, Shanghai — East Asia business hub |
| JST | Japan Standard Time | UTC +9 | Tokyo — finance & tech hub |
| AEST / AEDT | Australian Eastern (Daylight) Time | UTC +10 / +11 | Sydney, Melbourne — APAC regional business |
Why Time Zone Abbreviations Are Ambiguous
Unlike standardized identifiers (like America/New_York or Europe/London from the IANA tz database), abbreviations such as "CST" or "IST" are not globally unique. They can refer to different time zones depending on context — country, region, or even time of year (due to daylight saving time).
Common Ambiguous Time Zone Abbreviations
| Abbrev. | Common Meaning(s) | UTC Offset | Region(s) |
|---|---|---|---|
| CST | Central Standard Time / China Standard Time / Cuba Standard Time | UTC−6 / UTC+8 / UTC−5 | North America, China, Cuba |
| IST | Indian Standard Time / Irish Standard Time / Israel Standard Time | UTC+5:30 / UTC+1 / UTC+2 | India, Ireland, Israel |
| AST | Atlantic Standard Time / Arabia Standard Time | UTC−4 / UTC+3 | Caribbean, Canada, Middle East |
| PST | Pacific Standard Time / Philippine Standard Time | UTC−8 / UTC+8 | North America, Philippines |
| EST | Eastern Standard Time (North America / Australia) | UTC−5 / UTC+10 | North America, Australia |
✅ Best Practice
To avoid ambiguity, always:
- Use IANA tz identifiers — e.g.,
America/New_Yorkinstead of "EST" - Specify UTC offset explicitly — e.g.,
UTC−5when abbreviations must be used - Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset
Related Time Zone Conversions
About GMT to MST Time Conversion
Converting time from Greenwich Mean Time (GMT) to Mountain Standard Time (MST) is essential for UK to US Mountain region coordination. GMT is UTC+0, while MST is UTC-7, making MST 7 hours behind GMT.
This conversion is crucial for international business operations between the United Kingdom and the US Mountain region, including business centers in Denver, Salt Lake City, and Albuquerque. Whether you're scheduling meetings, coordinating project deadlines, or planning travel, our accurate IANA-based converter ensures you never miss the time difference.
Common Use Cases for GMT to MST Conversion
Business & Work
- Scheduling UK to US Mountain business meetings
- Coordinating London and Denver operations
- Managing international mining, energy, and tech operations
Personal & Travel
- Planning travel from UK to US Mountain region (Colorado, Utah, Arizona)
- Coordinating with US Mountain family and friends from UK
- Scheduling virtual events for UK-US Mountain audiences
Time Zone Information
Greenwich Mean Time (GMT)
- UTC Offset: UTC+0 (UTC+1 during BST)
- IANA Timezone: Europe/London
- Daylight Saving: Last Sunday in March to Last Sunday in October
- Major Cities: London, Edinburgh, Cardiff, Belfast, Dublin
- Coverage: United Kingdom and Ireland
Mountain Standard Time (MST)
- UTC Offset: UTC-7 (UTC-6 during MDT)
- IANA Timezone: America/Denver
- Daylight Saving: Second Sunday in March to First Sunday in November
- Major Cities: Denver, Salt Lake City, Albuquerque, Boulder, Fort Collins
- Coverage: Mountain United States and parts of Canada
Quick Reference: GMT to MST
Remember: MST is always 7 hours behind GMT
Frequently Asked Questions
What is the time difference between GMT and MST?
GMT (Greenwich Mean Time) is 7 hours ahead of MST (Mountain Standard Time). When it is noon (12:00 PM) in GMT, it is 5:00 AM in MST. This difference remains consistent because both regions adjust for daylight saving time at approximately the same periods.
How do I quickly calculate GMT to MST conversion?
Simply subtract 7 hours from the GMT time to get MST. For example: 8:00 PM GMT minus 7 hours equals 1:00 PM MST. If the result is negative or crosses midnight, you'll need to adjust to the previous day.
Does daylight saving time affect GMT to MST conversion?
GMT itself doesn't observe daylight saving time, but the UK (where GMT is based) changes to BST (British Summer Time, UTC+1) in summer. Meanwhile, MST changes to MDT (Mountain Daylight Time, UTC-6). During these periods, the time difference may shift by 1 hour. Our converter automatically handles these changes.
When should I use this GMT to MST converter?
Use this converter when scheduling international calls, planning business meetings, arranging travel, coordinating projects, or communicating with people in both the UK and US Mountain regions. It's particularly useful for companies operating between London and major cities like Denver, Salt Lake City, and Albuquerque.
What major cities are in the MST timezone?
MST covers the US Mountain region and includes major cities like Denver, Salt Lake City, Albuquerque, Boulder, and Fort Collins. The Mountain timezone is home to major energy, mining, and tech industries. Arizona does not observe daylight saving time and uses MST year-round.
How does MST differ from other US timezones?
MST is UTC-7 (or MDT at UTC-6 during daylight saving). It lies between CST (Central, UTC-6) and PST (Pacific, UTC-8) in the US. If you need conversions with other timezones, our GMT to CST and GMT to PST converters are also available.
Pro Tips
- • When scheduling early morning meetings with GMT colleagues, remember MST is 7 hours behind—7 AM GMT is midnight MST.
- • Use online calendars with timezone support to automatically show meeting times in both GMT and MST.
- • Peak overlap hours are typically 12 PM-4 PM MST / 7 PM-11 PM GMT for convenient business communication.
- • Arizona uses MST year-round (no daylight saving), while other Mountain states switch to MDT in summer.
- • The Mountain region has significant mining and energy operations, making this conversion important for those industries.
- • Always specify "GMT" or "MST" when scheduling to avoid confusion with other similar-sounding timezones.
Update Logs
View the latest updates and features