Convert GMT to MST
See the GMT to MST time difference, use the hour-by-hour conversion table, and schedule meetings across UTC+0 and UTC-7.
How to Convert GMT to MST
Open the GMT to MST converter: Go to https://www.xconvert.com/time-converter/gmt-to-mst-converter. The page loads with GMT and MST already shown in the visual comparison grid, which is useful if you are scheduling a call between London-based teams using GMT references and colleagues in Arizona or other Mountain Standard Time locations that stay on UTC-7 year-round.
Add comparison cities if your meeting involves more regions: Click + Add City and search for places such as London, Phoenix, and Denver. This is especially helpful for multinational operations in finance, SaaS support, logistics, and engineering, where one team may use GMT for coordination while North American teams may be split between fixed MST locations like Phoenix and seasonally changing Mountain Time cities like Denver.
Drag to select the meeting window on the grid: Click Select, then drag across the GMT row to highlight a time range in purple, such as 9:00 AM to 11:00 AM GMT. The grid will show that this equals 2:00 AM to 4:00 AM MST, making it clear that an early-morning GMT meeting is usually impractical for Mountain Standard Time participants, while 4:00 PM to 6:00 PM GMT converts to 9:00 AM to 11:00 AM MST, which is much better for business calls.
Export and share the selected time: After selecting a range, use the export options for ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link. This is useful when sending a confirmed meeting slot to a remote team, a client in the US Mountain region, or a travel group that needs the event to appear automatically in each person’s local calendar.
Understanding the GMT to MST Time Difference
GMT is UTC+0, while MST is UTC-7, so MST is 7 hours behind GMT. That means when it is 12:00 PM noon in GMT, it is 5:00 AM in MST, and when it is 6:00 PM GMT, it is 11:00 AM MST. This fixed relationship applies only when you are comparing true GMT with true MST.
Daylight saving time is the main reason people get confused. GMT itself does not observe daylight saving time, but many places in the Mountain Time region switch between MST (UTC-7) and MDT, Mountain Daylight Time (UTC-6). In the United States and Canada, daylight saving time in Mountain Time areas typically begins on the second Sunday in March and ends on the first Sunday in November, so during that period the difference between GMT and local Mountain clocks in those DST-observing places becomes 6 hours instead of 7.
This matters because not every place in the Mountain region handles DST the same way. Arizona, except the Navajo Nation, stays on MST all year, so Phoenix remains UTC-7 in both summer and winter. By contrast, cities such as Denver, Calgary, and Salt Lake City observe DST, so if you are coordinating with those cities in July, you are usually comparing GMT to MDT, not MST.
Best Times for Calls and Meetings Between GMT and MST
Because MST is 7 hours behind GMT, the most practical overlap usually happens in late afternoon GMT and morning MST. A standard MST workday of 9:00 AM to 5:00 PM MST corresponds to 4:00 PM to 12:00 AM GMT, which means the strongest same-day overlap for both sides is often 4:00 PM to 5:00 PM GMT = 9:00 AM to 10:00 AM MST if both teams keep traditional office hours.
For broader scheduling flexibility, 4:00 PM to 7:00 PM GMT = 9:00 AM to 12:00 PM MST is usually the best meeting block. This window works well for customer support handoffs, software sprint check-ins, legal reviews, and vendor calls because the GMT side is still within the business day while the MST side is in its core morning productivity hours.
Earlier GMT times are usually poor for live collaboration. For example, 9:00 AM GMT = 2:00 AM MST, 12:00 PM GMT = 5:00 AM MST, and 2:00 PM GMT = 7:00 AM MST, so a Europe-first morning meeting often forces Mountain participants into pre-work hours. If your team includes executives, sales staff, or operations managers in Arizona, pushing the meeting to 4:00 PM or later GMT usually improves attendance and response quality.
If the other side is not on fixed MST but on a DST-observing Mountain city, re-check the date before sending invites. In summer, a meeting set for 4:00 PM GMT lands at 10:00 AM MDT rather than 9:00 AM MST, which can actually make the overlap easier for teams in Denver, Edmonton, or Albuquerque. This is why using the date picker in the converter is important when scheduling quarterly reviews, recurring client calls, or cross-border logistics updates.
Frequently Asked Questions
What is the time difference between GMT and MST?
The standard time difference is 7 hours, with MST 7 hours behind GMT. If it is 3:00 PM GMT, it is 8:00 AM MST. This applies when you are comparing GMT to true Mountain Standard Time, such as in Arizona for most of the state.
When is 9 AM GMT in MST?
9:00 AM GMT is 2:00 AM MST on the same calendar day. That is why 9 AM GMT is generally too early for business meetings with teams working standard office hours in MST locations. If you need a practical live meeting, moving the GMT time to late afternoon usually works much better.
Does the difference between GMT and MST change during daylight saving time?
If you are comparing GMT to true MST, the difference stays 7 hours because MST is UTC-7. However, many North American Mountain Time locations switch to MDT (UTC-6) from roughly March to November, specifically from the second Sunday in March to the first Sunday in November in the US and Canada. During those months, the difference between GMT and those local clocks becomes 6 hours, not 7.
What is the best meeting time between GMT and MST?
For most business use cases, the best overlap is 4:00 PM to 7:00 PM GMT, which equals 9:00 AM to 12:00 PM MST. This window is strong for project standups, account management calls, and operations meetings because it avoids very early MST hours and still fits within a normal GMT workday. If the GMT team can only meet earlier, expect reduced overlap and more need for asynchronous follow-up.
Is GMT the same as UK time all year?
No, GMT matches UK time only during the part of the year when the UK is on Greenwich Mean Time. The UK switches to British Summer Time (BST, UTC+1) from the last Sunday in March to the last Sunday in October, so during that period UK local time is one hour ahead of GMT. This distinction matters if someone says “London time” instead of explicitly saying GMT.
Why does Phoenix show a different result from Denver when comparing to GMT?
Phoenix is in Arizona, which stays on MST (UTC-7) for most of the state all year and does not observe daylight saving time. Denver, on the other hand, follows seasonal clock changes, using MST in winter and MDT in summer. As a result, GMT compared with Phoenix stays at a 7-hour difference, while GMT compared with Denver becomes a 6-hour difference during the DST months.
How can I schedule a recurring meeting between GMT and MST without mistakes?
Use the converter’s date picker to check both winter and summer dates before confirming a recurring schedule. Then drag a time block on the grid and export it through ICS, Google Calendar, Gmail, Copy to clipboard, or Share link so participants receive the meeting in local time. This is especially important for recurring meetings involving Arizona, Colorado, or mixed North American teams where some participants observe DST and others do not.