Convert GMT to MST
See the time difference from Greenwich Mean Time to Mountain Standard Time, check matching hours, and plan calls across UTC+0 and UTC-7.
How GMT to MST Works
Convert Greenwich Mean Time (UTC+0) to Mountain Standard Time (UTC-7) with a 7-hour difference. The converter updates matching times automatically so you can read both zones side by side.
Hour-by-Hour Time Table
Use the visual grid and hour-by-hour table to compare GMT and MST across the day. Quickly scan overlapping business hours, then export selected times with ICS download or Google Calendar and Gmail support.
Schedule Meetings Accurately
Plan meetings between GMT and MST with automatic timezone adjustment and DST tracking where applicable. Historical and current offset rules are based on the IANA timezone database for reliable conversions.
How to Convert GMT to MST
Open the GMT to MST converter: Go to https://www.xconvert.com/time-converter/gmt-to-mst-converter to see Greenwich Mean Time and Mountain Standard Time on a visual 24-hour comparison grid. This page is useful when you need to line up a call between teams in the United Kingdom and western North America, or when you are scheduling support coverage across GMT-based and MST-based business hours.
Add comparison cities: Click + Add City and search for cities that matter to your workflow, such as London for UK business, Denver or Phoenix for Mountain-region operations, or Mexico City for cross-border coordination in North America. This is especially helpful for industries like software, logistics, customer support, and energy, where teams in GMT countries and MST countries often need a shared handoff window.
Select a meeting window on the grid: Use the Select button to enter selection mode, then drag across the colored timeline to highlight a time range in purple. For example, dragging from 9:00 GMT to 12:00 GMT shows the corresponding 2:00 MST to 5:00 MST, which makes it easy to see that an early GMT work block lands in the pre-dawn to early-morning period in MST and may not suit a live meeting.
Adjust and export the selected time: Drag the center of the purple selection to move it, or pull the left and right handles to resize it until you find a workable overlap, then use the export options: ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link. That makes it simple to send a confirmed meeting slot to a distributed team, add it to a calendar invite, or share a link with clients so everyone sees the same GMT-to-MST comparison.
Understanding the GMT to MST Time Difference
Greenwich Mean Time is UTC+0, and Mountain Standard Time is UTC-7. That means MST is 7 hours behind GMT, and equivalently, GMT is 7 hours ahead of MST.
In practical terms, the conversion follows a consistent standard-time relationship: 9:00 GMT = 2:00 MST, 12:00 GMT = 5:00 MST, 15:00 GMT = 8:00 MST, and 18:00 GMT = 11:00 MST. These examples are useful for planning morning updates from GMT-based teams and understanding how they land much earlier in the day for colleagues working on MST.
Both abbreviations are standard-time labels rather than daylight-saving labels. GMT is the standard-time abbreviation, and its daylight-saving counterpart is BST; MST is the standard-time abbreviation, and its daylight-saving counterpart is MDT. Because of that, the GMT-to-MST difference does not stay the same year-round in places that observe daylight saving time, and the difference changes during the months when BST or MDT is in effect rather than standard time.
GMT is used across a broad set of countries including the United Kingdom, Ireland, Iceland, Ghana, Senegal, Sierra Leone, Liberia, Mali, Mauritania, Guinea, Guinea-Bissau, Gambia, Togo, Burkina Faso, Sao Tome and Principe, Saint Helena, Guernsey, Jersey, Isle of Man, and Ivory Coast. MST is used in parts of Canada, Mexico, and the United States, so this conversion often matters for transatlantic business, travel coordination, and support teams serving customers across Europe and western North America.
Best Times for Calls and Meetings Between GMT and MST
Because MST is 7 hours behind GMT, early business hours in GMT map to very early morning in MST. The examples make that clear: 9:00 GMT = 2:00 MST and 12:00 GMT = 5:00 MST, so a typical morning block in GMT is usually too early for a standard workday meeting in Mountain Standard Time.
A more realistic overlap starts later in the GMT day. 15:00 GMT = 8:00 MST and 18:00 GMT = 11:00 MST, which means late afternoon in GMT aligns with the morning work period in MST. For many remote teams, this makes the 15:00-18:00 GMT range the most practical window for live meetings, status reviews, and customer calls.
This pattern is especially relevant for companies coordinating between the United Kingdom and operations in the United States, Canada, or Mexico. A UK-based product manager, sales team, or agency can use the late-afternoon GMT window to reach engineering, operations, or client teams in the Mountain time region without forcing either side into a late-night meeting.
If you are planning recurring meetings, use the grid to compare a few candidate windows rather than relying on memory. A slot that feels normal in GMT can easily fall outside standard office hours in MST, and the visual timeline makes it obvious whether you are scheduling into night, early morning, or a workable overlap.
Frequently Asked Questions
What is the time difference between GMT and MST?
The time difference is 7 hours. MST is 7 hours behind GMT, which also means GMT is 7 hours ahead of MST. This is the key relationship to remember when scheduling meetings, deadlines, or travel plans between Greenwich Mean Time regions and Mountain Standard Time regions.
When is 9 AM GMT in MST?
9:00 GMT = 2:00 MST. This conversion shows why morning meetings in GMT can be difficult for teams in Mountain Standard Time, since 9 AM in GMT falls in the middle of the night or very early morning for many people working in western North America.
When is 12 PM GMT in MST?
12:00 GMT = 5:00 MST. For business planning, that means a noon update from a GMT-based office still reaches MST teams before a normal workday begins, so it is better suited for asynchronous communication than a live call.
When is 3 PM GMT in MST?
15:00 GMT = 8:00 MST. This is one of the more practical conversion points for real-time collaboration because it places the GMT team in mid-afternoon and the MST team at the start of the business day.
When is 6 PM GMT in MST?
18:00 GMT = 11:00 MST. That makes early evening in GMT a strong option for same-day meetings with Mountain Standard Time participants, particularly for sales calls, project reviews, and cross-regional check-ins.
Does the difference between GMT and MST change during daylight saving time?
Yes, it can change because both GMT and MST are standard-time abbreviations. GMT changes to BST in daylight saving periods, and MST changes to MDT in daylight saving periods, so the GMT-to-MST relationship does not remain fixed during the months when those daylight-saving counterparts are in use.
What is the best meeting time between GMT and MST?
Using the provided examples, the strongest overlap for live meetings is generally later in the GMT day. Since 15:00 GMT = 8:00 MST and 18:00 GMT = 11:00 MST, the 15:00 to 18:00 GMT window usually works best for teams that want to meet during normal morning hours in MST while staying within the afternoon workday in GMT.
Which countries use GMT and which countries use MST?
GMT is used in countries and territories including the United Kingdom, Ireland, Iceland, Ghana, Senegal, Sierra Leone, Liberia, Mali, Mauritania, Guinea, Guinea-Bissau, Gambia, Togo, Burkina Faso, Sao Tome and Principe, Saint Helena, Guernsey, Jersey, Isle of Man, and Ivory Coast. MST is used in parts of Canada, Mexico, and the United States, which is why this conversion is common in international business, aviation planning, and remote team scheduling.