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New York vs London Time Difference
A live, side-by-side look at the gap between New York and London — usually five hours, briefly four during the short window each spring and autumn when the US and UK change their clocks on different dates.
New York
America/New_York
London
Europe/London
Calculating the live gap…
The busiest four hours in global finance
New York and London are the two largest financial centers on Earth, and their trading days barely touch. The New York Stock Exchange runs 9:30 a.m. to 4:00 p.m. Eastern; the London Stock Exchange runs 8:00 a.m. to 4:30 p.m. local. Because London is normally five hours ahead, that leaves roughly four hours — New York's 9:30 a.m. open until London's 4:30 p.m. close — when both exchanges are simultaneously live. Currency traders call this stretch the London-New York overlap, and it's widely cited as the single most liquid window in the entire 24-hour foreign exchange market, precisely because it's the only time both centers are trading at once.
Why the gap isn't always five hours
Both cities observe daylight saving time, but neither moves its clock on the same date as the other. The United Kingdom's clocks change on the last Sunday of March and the last Sunday of October. The United States changes on the second Sunday of March and the first Sunday of November — roughly two to three weeks earlier in spring, and one week later in autumn. During those mismatched windows, only one side has shifted its clock, so the usual five-hour gap briefly narrows to four.
Both dates above are calculated live from each zone's actual clock-change rules for this year — not hard-coded — so the narrow-gap windows they imply will stay correct every year without anyone having to update this page.
Best time to call, hour by hour
The table below runs through a full New York day and shows the matching London time for each hour, with the rows where both cities fall inside a typical 9:00–17:00 workday highlighted.
| New York time | London time | Both in business hours? |
|---|---|---|
| Calculating… | ||
For most of the year that leaves a workable window from about 9:00 a.m. to noon in New York (2:00 p.m. to 5:00 p.m. in London). Anything scheduled for New York's afternoon lands in London's evening, and anything scheduled for London's morning lands well before New York's alarm clock goes off.
How we calculate this page: both live clocks, the current gap, the DST transition dates, and the hour-by-hour overlap table are all computed directly from the IANA America/New_York and Europe/London time zone data via your browser on every page load — nothing here is a fixed, hard-coded figure.
Frequently asked questions
What is the time difference between New York and London right now?
Usually five hours, with London ahead of New York. For a few weeks each spring and autumn the gap narrows to four hours, because the US and UK change their clocks on different Sundays. The live clocks above always show today's actual gap.
Why isn't the New York-London time difference always five hours?
Both cities observe daylight saving time, but on different calendars. The UK's clocks change on the last Sundays of March and October; the US changes on the second Sunday of March and the first Sunday of November. In the gap between those dates, only one side has "sprung forward" or "fallen back," temporarily shrinking the usual five-hour gap to four.
What is the best time to schedule a call between New York and London?
Roughly 9:00 a.m. to noon in New York, which lands at 2:00 p.m. to 5:00 p.m. in London most of the year. That four-to-five-hour window is the only stretch of the day when both cities are inside a typical 9-to-5 workday at the same time.
Is New York-London the busiest overlap window in global finance?
Yes. The few hours when both the New York Stock Exchange and the London Stock Exchange are open simultaneously are widely cited by foreign-exchange traders as the highest-liquidity window of the entire 24-hour trading day, since it's the only time the world's two largest financial centers are both live at once.
How many hours ahead is London compared to New York?
London is ahead of New York by five hours for most of the year (four hours during the brief DST-mismatch window each spring and autumn). London is never behind New York.
How do I convert New York time to London time?
Add five hours to New York time to get London time on an ordinary day (four hours during the short DST-mismatch window). For a guaranteed-accurate conversion on any specific date, use the time zone converter on WatchTime Online.
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