The short answer: London is 5 hours ahead of New York for most of the year. When it is 12:00 noon there it is usually 5:00 PM in London. The best overlap is the American morning against London afternoon: a call at 9:00 AM Eastern lands at 2:00 PM London - comfortable working hours on both sides.
London and New York are the classic transatlantic pair, and the maths is unusually clean: most of the year it is a simple five-hour jump. London keeps GMT in winter and BST in summer; the American city keeps EST in winter and EDT in summer. Because both cities move their clocks, the gap stays steady at five hours almost all year.
How far ahead is London?
For the great majority of the year the offset is a flat five hours, London ahead. The only exceptions are two short stretches: a few weeks each spring after the US springs forward but before the UK does, and a brief window in autumn, when the gap narrows to four hours.
| Period | London is ahead of New York by |
|---|---|
| Most of the year (clocks aligned) | 5 hours |
| Spring (US ahead, UK not yet) | 4 hours |
| Autumn (brief overlap) | 4 hours |
The five-hour figure is the one to remember. The four-hour windows last only about three weeks in spring and a few days in autumn, so for almost any date you pick, five hours is correct.
The best windows to meet
Because London is ahead, the American morning is London's afternoon. That makes the late morning there the cleanest overlap: both sides are firmly inside the working day.
| In New York (EST/EDT) | In London (GMT/BST) |
|---|---|
| 9:00 AM | 2:00 PM |
| 12:00 noon | 5:00 PM |
| 5:00 PM | 10:00 PM |
A 9:00 AM start in New York is 2:00 PM in London, a relaxed early afternoon. By noon it is already 5:00 PM in London, near the end of the British workday, so anything later is best kept short. Aim for roughly 9:00 AM to noon Eastern time (2:00 to 5:00 PM London) for the most comfortable shared hours.
Work call vs personal call
For a work call, the late morning on the US side is ideal: 9:00 to 11:00 AM Eastern is 2:00 to 4:00 PM in London, well inside business hours for both. For a personal call to family or friends in London, the same window works, or you can push to the early US afternoon, knowing it is already evening across the Atlantic.
Both cities observe daylight saving, but on different dates. The US changes its clocks before the UK in spring and after it in autumn, so for a few weeks the usual 5-hour gap becomes 4 hours. A recurring call set during the normal five-hour period will land an hour off in those windows. See our note on the New York to London DST gap.
Stop checking this every time
If you work across London and New York regularly, the five-hour shift is easy to remember until daylight saving briefly breaks it. Atlas keeps both cities side by side in your Mac menu bar, shades the hours when both sides are awake, and writes any meeting to your calendar in both local times. One glance tells you whether now is a good time to call. For the wider picture, see our guide to the USA to UK time zone difference.
Frequently asked
How many hours ahead is London of New York?
What time is it in London when it is 12 noon in New York?
What is the best time for a London and New York meeting?
Why does the London to New York gap change?
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