GMT to EST Converter
Convert GMT to Eastern Time for any date. The gap changes with the US seasons — Eastern is 5 hours behind GMT in winter and 4 hours behind in summer — because GMT itself never moves. One warning this page takes seriously: GMT is not London time in summer.
Convert Greenwich Mean Time to Eastern Time
It opens on the current Greenwich Mean Time time — pick any date and time to convert it.
Your converted time will appear here.
The GMT to EST difference, exactly
The gap, the day change and the offsets — shown with every result.
Winter: minus 5 hours
12:00 GMT is 7:00 AM EST. GMT times before 5:00 AM are the previous day in the East.
Summer: minus 4 hours
12:00 GMT is 8:00 AM EDT while US daylight saving is in force.
London is different in summer
When London is on BST, 12:00 in London is 7:00 AM EDT — an hour different from GMT.
About GMT to EST conversion
GMT — Greenwich Mean Time — is the historic reference time from which all offsets are measured, and it has one defining property: it never changes. GMT is UTC+0 in January and in July alike. Eastern Time, on the other hand, moves: EST (UTC-5) in winter, EDT (UTC-4) in summer. So converting GMT to Eastern means subtracting five hours in winter (12:00 GMT is 7:00 AM in New York) and four in summer (12:00 GMT is 8:00 AM) — and the date you enter is what decides. This converter uses GMT as UTC and the real time in New York, so both seasons are handled exactly.
The confusion worth naming: people often write “GMT” when they mean the time in London. Those are the same only in winter — from the last Sunday in March to the last Sunday in October, London is on British Summer Time (BST, UTC+1), an hour ahead of GMT. A “12:00 GMT” webinar in July is at 8:00 AM in New York if it truly means GMT, but 7:00 AM if the organiser meant London time. If your source is a UK company, London is in this converter’s zone lists — convert from London and the summer answer will be the right one.
On a January date (EDT in summer is one hour later):
| GMT | EST (January) |
|---|---|
| 12:00 AM | 7:00 PM (previous day) |
| 5:00 AM | 12:00 AM |
| 12:00 PM | 7:00 AM |
| 6:00 PM | 1:00 PM |
| 11:00 PM | 6:00 PM |
Frequently asked questions
The difference, daylight saving and the cases people trip over.
How do I convert GMT to EST?
Subtract five hours in winter: 12:00 GMT is 7:00 AM EST. In summer, when Eastern observes daylight saving (EDT), subtract four instead: 12:00 GMT is 8:00 AM EDT. GMT itself is the same all year — it is the Eastern side that moves. This converter chooses the offset from the date you enter.
Is GMT the same as UTC?
For everyday conversion, yes — GMT and UTC read the same time (UTC is the technical standard that replaced GMT, and both are +0). The difference that matters in practice is not GMT versus UTC but GMT versus London time in summer.
Is GMT the same as London time?
Only in winter. London is on GMT from late October to late March, and on British Summer Time (BST, UTC+1) for the rest of the year. If a UK source says “GMT” in July, they usually mean London time — convert from London in the zone list to get that answer.
Why does the GMT to EST difference change?
Because only one side moves. GMT is fixed all year, while Eastern Time springs forward to EDT (UTC-4) in March and falls back to EST (UTC-5) in November. The gap is therefore 4 hours in summer and 5 in winter.
What is 12:00 GMT in EST?
7:00 AM in winter (EST) and 8:00 AM in summer (EDT), on the same calendar day. And 2:00 AM GMT is 9:00 PM EST the previous evening in winter.
Is anything I enter stored?
No. The conversion runs entirely in your browser; nothing is uploaded or saved.