GMT to EST, UTC+0 in New York.

GMT to EST means turning Greenwich Mean Time, UTC+0, into US Eastern time. New York is 5 hours behind GMT when it is on EST, UTC-5, and 4 hours behind when it is on EDT, UTC-4. So 15:00 GMT is 10:00 AM EST in winter and 11:00 AM EDT in summer. This page reads GMT as the fixed UTC+0 zone, which is how event organisers and log files give it. If you mean the clock in London, which is on BST (UTC+1) in summer, change Read GMT as to London time.

How to use the GMT to EST converter

1. In the left box, GMT, type a Time and a Date. The right box, EST, shows New York.
2. Read GMT as starts on GMT only (UTC+0 all year). Choose London time (GMT or BST) if the time comes from someone in the UK.
3. Read EST as starts on Eastern Time (EST or EDT), the clock in New York. EST only (UTC-5 all year) holds the offset fixed.
4. Check the Meeting planner for the hours when both sides are at work. The UK day ends when the US day is only half over, so the shared window is short.
5. Print the chart prints every GMT hour of the date beside the New York time. Copy result, Copy link and Add to calendar (.ics) pass the moment on.
6. Swap turns the page around to start from New York.

The gap is 5 hours, then 4

With GMT held at UTC+0, the gap to New York depends only on New York. It is 5 hours from the first Sunday in November to the second Sunday in March, and 4 hours in between. The 4 hour stretch runs from Sunday 8 March 2026 to Sunday 1 November 2026 in 2026, and from Sunday 14 March 2027 to Sunday 7 November 2027 in 2027. Worked example, 15:00 GMT on Tuesday 20 October 2026: subtract 4 hours for EDT and you get 11:00 AM. On Tuesday 20 January 2026 subtract 5 hours for EST and you get 10:00 AM.

When you mean London

The UK moves its clocks too. The gov.uk page says the clocks go forward at 1am on the last Sunday in March and back at 2am on the last Sunday in October, so London is on BST in summer and on GMT in winter. In 2026 the dates are Sunday 29 March 2026 and Sunday 25 October 2026, and in 2027 they are Sunday 28 March 2027 and Sunday 31 October 2027. With London time selected, the gap to New York is 5 hours almost all year, because both move in the summer. Compare 15:00 on Tuesday 20 October 2026: London is on BST, so that is 10:00 AM in New York, a gap of 5 hours, where 15:00 GMT would be 11:00 AM. One reading is an hour off the other, which is why it matters to know what a sender means.

The weeks when London and New York are 4 hours apart

The US and the UK do not change on the same dates. The US moves earlier in March and later in the autumn than the UK. So London is 4 hours ahead of New York, not 5, from Sunday 8 March 2026 until Sunday 29 March 2026, and again from Sunday 25 October 2026 until Sunday 1 November 2026. Example: 15:00 London time on Wednesday 18 March 2026 is 11:00 AM in New York, because the US is on EDT while the UK is still on GMT. The list When the difference changes shows these dates for this year and next.

Typical times, summer and winter

The UK working day ends at about 17:00 GMT, which is noon in New York in winter and 1:00 PM in summer. That makes the shared window short: 14:00 to 17:00 GMT, which is 9:00 AM to 12:00 PM in New York in winter.

Why EST is not the whole answer

EST is UTC-5, but New York is on EDT in summer. If a message says 14:00 GMT, 9:00 AM EST and the date is in July, the two cannot both be right. Use the date to decide, or write GMT as UTC+0 and ET for New York.

Sources, checked 18 Oct 2026. The United States rule is in 49 CFR Part 71, section 71.2: standard time moves ahead one hour at 2 a.m. on the second Sunday in March and ends at 2 a.m. on the first Sunday in November. The US Department of Transportation says a state may exempt itself by state law. The UK dates are from gov.uk. The offsets and the zone names come from the IANA time zone database (version 2026e), the same data your browser uses.

Other pairs: IST to EST, CST to EST and EST to PST.