Greenwich Mean Time is 7 hours ahead of Mountain Time.

Frequently asked

Quick answers about converting between Greenwich Mean Time and Mountain Time. Can't find what you need? Email [email protected].

What is the time difference between Greenwich Mean Time and Mountain Time?

Greenwich Mean Time is 7 hours ahead of Mountain Time right now. We always show the live, daylight-saving-correct difference, so this figure already accounts for whichever side is observing summer time today.

When it's 9am in Greenwich Mean Time, what time is it in Mountain Time?

9am in Greenwich Mean Time is 2am in Mountain Time. Use the hour-by-hour table above to read any other time across — find the row and read the matching cell in the other column.

What's the best time for a call between Greenwich Mean Time and Mountain Time?

4pm–5pm in Greenwich Mean Time lines up with 9am–10am in Mountain Time — both sides are inside a 9-to-5 working day.

Does this account for daylight saving time?

Yes. We track every clock change in both places, so the abbreviations you see — BST and MDT — are the ones actually in effect right now, not a fixed all-year value. When either side changes its clocks, this page updates automatically.

Why is the date sometimes different on each side?

When two places are far enough apart, the same moment can fall on different calendar days. That is why some conversions are marked "previous day" or "next day" — it is the same instant in time, read off two clocks that crossed midnight at different points.