London to New York Time Difference
London is 5 hours ahead of New York for most of the year. When it changes to 4 hours, and the golden 3-hour overlap window for transatlantic calls.
The short answer
London is 5 hours ahead of New York for roughly 49 weeks of the year. When it is 15:00 in London, it is 10:00 AM in New York.
During the 2–3 week daylight saving transitions in March and October/November, the difference briefly shrinks to 4 hours.
Hour Comparison Table (London vs. New York)
| London Time (GMT / BST) | New York Time (EST / EDT) | Work Overlap Status |
|---|---|---|
| 09:00 (London morning) | 04:00 AM (NYC night) | NYC sleeping |
| 13:00 (London lunch) | 08:00 AM | NYC starts workday |
| 14:00 – 17:00 | 09:00 AM – 12:00 PM | Golden business overlap window |
| 17:30 (London EOD) | 12:30 PM (NYC lunch) | London signing off |
| 22:00 (London night) | 17:00 (NYC EOD) | NYC signing off |
The Transatlantic DST Offset Gap
The United States starts Daylight Saving Time on the second Sunday in March, while the United Kingdom advances its clocks on the last Sunday in March. In autumn, the UK falls back on the last Sunday in October, while the US falls back on the first Sunday in November.
During these spring and autumn transition gaps, London is only 4 hours ahead of New York.
Scheduling Strategy for Global Teams
The ideal window for live calls between the UK and the US East Coast is 14:00 to 17:00 London time (09:00 to 12:00 New York time). This provides 3 productive hours without requiring either team to work outside normal office hours.
Timezone: World Clock Widget
A world clock, converter and live day/night map for iPhone — 325 cities, offline, no account.
Figures on this page are computed from the IANA time zone database. Last generated 2026-08-20.