Convert any time between GMT and EST, with a full 24-hour table and the hours when both sides are actually at work.

GMT to EST Time Converter

EST is 5 hours behind GMT. The UK and Ireland are currently on BST (UTC+1:00), and The US East Coast is currently on EDT (UTC-4:00).

GMT
Greenwich Mean Time
01:04:42 PM
Sunday, October 11, 2026
UTC+1:00
-5:00
hours difference
⇆ Reverse
EST
Eastern Standard Time
08:04:42 AM
Sunday, October 11, 2026
UTC-4:00

Best Time to Call Between GMT and EST

Both zones are inside normal business hours between 2:00 PM and 5:00 PM GMT — that's 9:00 AM to 12:00 PM EST. That's a 3-hour window.

both at work GMT only EST only neither  —  hours along the strip are GMT.

GMT to EST: Full 24-Hour Conversion Table

Shaded rows are working hours; the darker shade marks the hours when both zones are at work.

GMTESTWorking hours
12:00 AM 7:00 PM prev day —
1:00 AM 8:00 PM prev day —
2:00 AM 9:00 PM prev day —
3:00 AM 10:00 PM prev day —
4:00 AM 11:00 PM prev day —
5:00 AM 12:00 AM —
6:00 AM 1:00 AM —
7:00 AM 2:00 AM —
8:00 AM 3:00 AM —
9:00 AM 4:00 AM GMT only
10:00 AM 5:00 AM GMT only
11:00 AM 6:00 AM GMT only
12:00 PM 7:00 AM GMT only
1:00 PM 8:00 AM GMT only
2:00 PM 9:00 AM Both zones
3:00 PM 10:00 AM Both zones
4:00 PM 11:00 AM Both zones
5:00 PM 12:00 PM EST only
6:00 PM 1:00 PM EST only
7:00 PM 2:00 PM EST only
8:00 PM 3:00 PM EST only
9:00 PM 4:00 PM EST only
10:00 PM 5:00 PM —
11:00 PM 6:00 PM —

What GMT and EST Actually Are

GMT — Greenwich Mean Time

The UK and Ireland in winter, plus Iceland, Portugal and much of West Africa. Standing at UTC as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, October 25, 2026, to GMT. Often used loosely as a synonym for UTC. They differ by less than a second, so for scheduling they are interchangeable.

Britain ran an experiment from 1968 to 1971 on permanent UTC+1, abandoning GMT entirely. It was scrapped after complaints about dark winter mornings in Scotland.

EST — Eastern Standard Time

New York, Toronto, Washington DC, Atlanta, Miami, Boston. Standing at UTC-5:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, November 1, 2026, to EST. Australia also uses EST for its own Eastern Standard Time (UTC+10), now more often written AEST.

Eastern Standard Time is only actually in force from early November to mid-March. For the other eight months the same region is on EDT, which is why so many EST conversions are quietly wrong.

What This Means in Practice

Both sides change clocks, on different dates

Both regions observe daylight saving but do not switch on the same day, so for a week or two each spring and fall the gap between them is an hour different from the rest of the year. Those short windows are where recurring invitations quietly break.

Frequently Asked Questions

What is the time difference between GMT and EST?

EST is 5 hours behind GMT.

What is 9:00 AM GMT in EST?

9:00 AM GMT is 4:00 AM EST.

What are the best hours to schedule a call between GMT and EST?

Between 2:00 PM and 5:00 PM GMT, which is 9:00 AM to 12:00 PM EST. Both sides are inside normal business hours through that window.

Does the difference between GMT and EST change during the year?

Yes. Both regions observe daylight saving, and they do not switch on the same dates, so the gap shifts by an hour at least twice a year. The next clock change is on Sunday, October 25, 2026.

Does GMT always mean Greenwich Mean Time?

Often used loosely as a synonym for UTC. They differ by less than a second, so for scheduling they are interchangeable.

Does EST always mean Eastern Standard Time?

Australia also uses EST for its own Eastern Standard Time (UTC+10), now more often written AEST.

Converting between two time zones regularly? Bookmark this page — the clocks update live and the table follows daylight saving automatically.