MST to GMT Converter

Convert time between Mountain Standard Time (MST) and Greenwich Mean Time (GMT)

Mountain Standard Time (MST)

06:59:49
UTC +0
Dec 07, 2025
America/Denver

Greenwich Mean Time (GMT)

06:59:49
UTC +0
Dec 07, 2025
Europe/London

Time Difference

Greenwich Mean Time (GMT) is 0 hours ahead of Mountain Standard Time (MST)

Select Date

Select Time

Quick Reference

MSTGMT
19:0002:00
21:0004:00
23:0006:00
01:0008:00
03:0010:00
05:0012:00
07:0014:00
09:0016:00
11:0018:00
13:0020:00
15:0022:00
17:0000:00

Top 10 Most Common Time Zones

AbbreviationFull NameUTC OffsetTypical Use
UTCCoordinated Universal TimeUTC ±0Global reference standard (servers, logs, APIs)
EST / EDTEastern (US) TimeUTC −5 / −4New York, Toronto — North American business hub
CST / CDTCentral (US) TimeUTC −6 / −5Chicago, Dallas — US central business region
PST / PDTPacific (US) TimeUTC −8 / −7San Francisco, Los Angeles — tech industry standard
GMT / BSTGreenwich Mean / British Summer TimeUTC 0 / +1UK, used globally as a reference with UTC
CET / CESTCentral European (Summer) TimeUTC +1 / +2Paris, Berlin, Amsterdam — EU business core
ISTIndia Standard TimeUTC +5:30India — major IT & outsourcing region
CSTChina Standard TimeUTC +8Beijing, Shanghai — East Asia business hub
JSTJapan Standard TimeUTC +9Tokyo — finance & tech hub
AEST / AEDTAustralian Eastern (Daylight) TimeUTC +10 / +11Sydney, 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 OffsetRegion(s)
CSTCentral Standard Time / China Standard Time / Cuba Standard TimeUTC−6 / UTC+8 / UTC−5North America, China, Cuba
ISTIndian Standard Time / Irish Standard Time / Israel Standard TimeUTC+5:30 / UTC+1 / UTC+2India, Ireland, Israel
ASTAtlantic Standard Time / Arabia Standard TimeUTC−4 / UTC+3Caribbean, Canada, Middle East
PSTPacific Standard Time / Philippine Standard TimeUTC−8 / UTC+8North America, Philippines
ESTEastern Standard Time (North America / Australia)UTC−5 / UTC+10North America, Australia

✅ Best Practice

To avoid ambiguity, always:

  • Use IANA tz identifiers — e.g., America/New_York instead of "EST"
  • Specify UTC offset explicitly — e.g., UTC−5 when abbreviations must be used
  • Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset

About MST to GMT Time Conversion

Converting time from Mountain Standard Time (MST) to Greenwich Mean Time (GMT) is essential for coordinating between the US Mountain region and the United Kingdom. MST is UTC-7, while GMT is UTC+0, making GMT 7 hours ahead of MST during the standard time period (November to March).

This converter uses the IANA timezone database to ensure accurate calculations for transatlantic business operations. Whether you're scheduling international meetings, managing distributed teams, or coordinating projects with the UK, this tool provides reliable real-time conversions for seamless global coordination.

Common Use Cases for MST to GMT Conversion

Business & Work

  • Scheduling transatlantic business meetings between Mountain region and UK
  • Coordinating with UK-based team members and remote workers
  • Managing international software development with London offices
  • Syncing with London financial markets and trading operations

Personal & Travel

  • Planning international travel from Mountain region to UK
  • Coordinating with friends and family in the UK
  • Attending UK-based conferences and virtual events
  • Tracking UK events and live broadcasts from Mountain region

Time Zone Information

Mountain Standard Time (MST)

  • UTC Offset: UTC-7
  • IANA Timezone: America/Denver
  • Daylight Saving: November to March (March to November uses MDT)
  • Major Cities: Denver, Salt Lake City, Albuquerque, Boise, Colorado Springs
  • Coverage: Mountain United States and parts of Canada

Greenwich Mean Time (GMT)

  • UTC Offset: UTC+0
  • IANA Timezone: Europe/London
  • Daylight Saving: GMT is standard time (UTC+0). BST (UTC+1) is March to October
  • Major Cities: London, Greenwich, Edinburgh, Belfast, Cardiff
  • Coverage: United Kingdom, Ireland, and parts of Western Europe

Quick Reference: MST to GMT

12:00 AM MST
7:00 AM GMT
9:00 AM MST
4:00 PM GMT
12:00 PM MST
7:00 PM GMT
6:00 PM MST
1:00 AM GMT (next day)

Note: GMT is always 7 hours ahead of MST (November - March). During daylight time (March - November), MDT is UTC-6, making GMT 6 hours ahead.

Frequently Asked Questions

What is the time difference between MST and GMT?

MST (Mountain Standard Time) is UTC-7, while GMT (Greenwich Mean Time) is UTC+0, making GMT 7 hours ahead of MST. This means when it is noon in Denver (MST), it is already 7:00 PM the same day in London (GMT).

How does MST differ from MDT?

MST (Mountain Standard Time) is UTC-7 and is observed during standard time (November to March), while MDT (Mountain Daylight Time) is UTC-6 and is observed during daylight saving time (March to November). This one-hour difference is important when scheduling across seasons.

Does GMT observe daylight saving time?

No, GMT (Greenwich Mean Time) does not observe daylight saving time. However, the UK uses BST (British Summer Time) during daylight saving periods. GMT remains UTC+0 year-round and is used as a global standard reference. During BST (late March to late October), the UK is UTC+1.

When does MST transition to MDT?

Mountain Standard Time (MST) transitions to Mountain Daylight Time (MDT) on the second Sunday in March at 2:00 AM. The reverse transition from MDT to MST occurs on the first Sunday in November at 2:00 AM. During MDT, the time difference with GMT is 6 hours instead of 7.

How do I convert MST to GMT manually?

To convert MST to GMT, simply add 7 hours to the MST time. For example, if it is 3:00 PM MST, the corresponding GMT time would be 10:00 PM (15:00 + 7 hours = 22:00). If the result exceeds 24 hours, subtract 24 hours and add 1 day.

Why is understanding MST to GMT conversion important?

Understanding MST to GMT conversion is crucial for coordinating with teams and businesses in the UK and Europe, international travel planning, virtual meetings across the Atlantic, and global communication. The 7-hour difference makes accurate conversion essential for business operations.

Pro Tips

  • • MST is only observed from November to March. From March to November, the Mountain region uses MDT (Mountain Daylight Time) with a 6-hour difference from GMT.
  • • GMT is equivalent to UTC (Coordinated Universal Time) and serves as the global reference time used for aviation and international business.
  • • The UK switches to BST (British Summer Time) at different dates than the US switches to MDT, so the time difference can vary by a few weeks during transition periods.
  • • When scheduling international meetings between Mountain US and UK, early morning MST (7-8 AM) aligns with late afternoon/evening GMT (2-3 PM), making it ideal for both regions.
  • • Use a converter like this one for daylight saving transitions to avoid miscalculations when MST switches to MDT and GMT switches to BST.
  • • Always verify whether your meeting participants are observing daylight saving time, as transition dates can vary between the US and UK by a few weeks.

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