MST to GMT Time Zone Converter
This converts US Mountain Time (Denver, Salt Lake City — locals say MT) to London time. London is normally 7 hours ahead of Mountain. Both places observe daylight saving but switch on different dates, so the gap is steady most of the year and slips by an hour only during two short windows in spring and fall. The converter tracks all of it for the date you pick.
Enter a date and time to convert.
Daylight saving is applied automatically for the date you pick. Labels like PST/EST name the zone (Pacific/Eastern); the real abbreviation shifts to PDT/EDT during daylight saving, and gmt here means London (GMT in winter, BST in summer) while utc stays fixed.
The time difference
London is ahead of US Mountain Time by 7 hours most of the year. Both sides observe daylight saving, which keeps the gap steady across the winter and summer anchors. The one wrinkle: the US switches on March 8 and November 1, 2026 while the UK switches on March 29 and October 25. During those short overlaps — roughly March 8–29 and October 25–November 1 — the gap is briefly off by an hour until both sides have changed.
A worked example
Take 9:00 AM in Denver. On January 15, 2026 that's 4:00 PM in London the same day. On July 15, 2026 it's also 4:00 PM in London — the clock result matches because both anchors fall in aligned periods, so the 7-hour gap holds.
Daylight saving & the abbreviation caveat
The slug says MST, the standard-time name, but Mountain Time runs as MDT from spring to fall, which is why locals just say "MT." London is GMT in winter and BST in summer. Because the US and UK change on different dates, the gap wobbles by an hour during the late-March and late-October windows. The converter sorts all of this out for whatever date you choose, so a result that looks an hour "off" during a changeover week is actually correct.
When you'll use it
This is the one for calls with UK colleagues, catching a Premier League kickoff, tracking London market hours, or timing a flight to Heathrow. It's also useful for anyone in Denver or Salt Lake working with a London-based client or team.
Frequently asked questions
How many hours ahead of Mountain Time is London?
Usually 7 hours ahead. That holds through most of winter and summer. It's only during the late-March and late-October changeover windows that the gap briefly becomes 8 or 6 hours.
Is London always called GMT?
No. London is GMT in winter and BST (British Summer Time) from late March to late October. It's the same city and the same converter — only the label changes.
Why is the gap off for a couple of weeks each spring and fall?
The US springs forward and falls back on different dates than the UK. For roughly two weeks in late March and late October, one side has switched and the other hasn't, so the usual 7-hour gap is off by an hour.