Time Zone Conversion: London to New York Made Simple
For most of the year, New York is five hours behind London: when it is 3pm in London, it is 10am in New York. For a few weeks each spring and autumn the gap shrinks to four hours, because the UK and the US change their clocks on different dates. This guide explains why, shows you how to convert any time by hand, and gives worked examples you can check against our free converter.
Why London and New York are usually five hours apart
Every time zone is defined as an offset from Coordinated Universal Time (UTC), the world’s reference clock. London and New York each use two offsets during the year: a standard (winter) time and a daylight saving (summer) time.
- London in winter: Greenwich Mean Time (GMT), which is UTC+0.
- London in summer: British Summer Time (BST), which is UTC+1.
- New York in winter: Eastern Standard Time (EST), which is UTC−5.
- New York in summer: Eastern Daylight Time (EDT), which is UTC−4.
In winter the difference is 0 − (−5) = 5 hours. In summer it is 1 − (−4) = 5 hours. Because both cities spring forward by one hour, the gap stays at five hours for the vast majority of the year. The trouble only starts when one city has changed its clocks and the other has not.
The weeks when the gap is only four hours
The two countries follow different rules for daylight saving:
- UK: clocks go forward at 1am GMT on the last Sunday of March and back at 2am BST on the last Sunday of October.
- US: clocks go forward at 2am local time on the second Sunday of March and back at 2am local time on the first Sunday of November.
So America springs forward two or three weeks before Britain, and falls back about a week after Britain. During those windows New York is on daylight time while London is on standard time, giving 0 − (−4) = 4 hours. The table below shows the exact dates for 2026 and 2027.
| Period | London | New York | New York is behind by |
|---|---|---|---|
| 1 Jan – 7 Mar 2026 | GMT (UTC+0) | EST (UTC−5) | 5 hours |
| 8 Mar – 28 Mar 2026 | GMT (UTC+0) | EDT (UTC−4) | 4 hours |
| 29 Mar – 24 Oct 2026 | BST (UTC+1) | EDT (UTC−4) | 5 hours |
| 25 Oct – 31 Oct 2026 | GMT (UTC+0) | EDT (UTC−4) | 4 hours |
| 1 Nov 2026 – 13 Mar 2027 | GMT (UTC+0) | EST (UTC−5) | 5 hours |
| 14 Mar – 27 Mar 2027 | GMT (UTC+0) | EDT (UTC−4) | 4 hours |
| 28 Mar – 30 Oct 2027 | BST (UTC+1) | EDT (UTC−4) | 5 hours |
| 31 Oct – 6 Nov 2027 | GMT (UTC+0) | EDT (UTC−4) | 4 hours |
| 7 Nov – 31 Dec 2027 | GMT (UTC+0) | EST (UTC−5) | 5 hours |
The changeover itself happens in the early hours of each Sunday, so a meeting on that Sunday morning is the one case where you should double-check with a tool rather than the table.
How to convert London time to New York time, step by step
You can convert any time between the two cities with four quick steps. Working through UTC feels slower at first, but it removes guesswork and works for any pair of time zones.
- Check the date. Use the table above to see whether each city is on standard or daylight time on that day.
- Convert the starting time to UTC. Subtract the source city’s offset. For London on BST, subtract 1 hour; on GMT, subtract nothing. For New York, add 5 hours on EST or 4 hours on EDT.
- Convert UTC to the destination city. Add the destination offset: add 1 hour for London on BST, or subtract 5 hours (EST) or 4 hours (EDT) for New York.
- Check the day. If the result goes below midnight or past 11:59pm, move the date back or forward by one day.
Once you are confident, the shortcut is simple: London to New York, subtract 5 hours (or 4 in the gap weeks); New York to London, add 5 hours (or 4).
Worked examples with real dates
Example 1: a winter call from London
You want to call a New York client at 3pm London time on Thursday 14 January 2027.
- Date check: mid-January, so London is on GMT (UTC+0) and New York is on EST (UTC−5).
- London to UTC: 15:00 − 0 = 15:00 UTC.
- UTC to New York: 15:00 − 5 = 10:00.
- Result: 10am on Thursday 14 January in New York.
Example 2: a meeting in the March gap weeks
A New York colleague books a stand-up for 9am their time on Tuesday 16 March 2027. What time is that in London?
- Date check: the US moved to EDT on 14 March, but the UK stays on GMT until 28 March. New York is UTC−4; London is UTC+0.
- New York to UTC: 09:00 + 4 = 13:00 UTC.
- UTC to London: 13:00 + 0 = 13:00.
- Result: 1pm in London, not the 2pm you would get by adding the usual five hours.
Example 3: a late-evening time that crosses midnight
A live stream starts at 9pm New York time on Sunday 6 June 2027. When should you tune in from London?
- Date check: June, so New York is on EDT (UTC−4) and London is on BST (UTC+1).
- New York to UTC: 21:00 + 4 = 25:00, which is 01:00 UTC on Monday 7 June.
- UTC to London: 01:00 + 1 = 02:00.
- Result: 2am on Monday 7 June in London. The date has moved forward a day, which is easy to miss.
Quick reference: office hours in both cities
This table converts common London times to New York for both the normal five-hour gap and the four-hour gap weeks.
| London time | New York (usual, 5 h behind) | New York (gap weeks, 4 h behind) |
|---|---|---|
| 08:00 (8am) | 03:00 (3am) | 04:00 (4am) |
| 12:00 (noon) | 07:00 (7am) | 08:00 (8am) |
| 13:00 (1pm) | 08:00 (8am) | 09:00 (9am) |
| 14:00 (2pm) | 09:00 (9am) | 10:00 (10am) |
| 15:00 (3pm) | 10:00 (10am) | 11:00 (11am) |
| 16:00 (4pm) | 11:00 (11am) | 12:00 (noon) |
| 17:00 (5pm) | 12:00 (noon) | 13:00 (1pm) |
| 18:00 (6pm) | 13:00 (1pm) | 14:00 (2pm) |
| 22:00 (10pm) | 17:00 (5pm) | 18:00 (6pm) |
If both offices work 9am to 5pm local time, the shared window is 2pm to 5pm in London (9am to noon in New York) for most of the year, widening to 1pm to 5pm London time (9am to 1pm in New York) during the gap weeks.
Common mistakes and UK vs US conventions
- Writing “EST” in summer. Americans often say “Eastern Time” or “EST” all year, but strictly EST is winter only; summer is EDT. If an invite says “10am EST” in July, it almost always means Eastern Time, which is EDT.
- Saying “GMT” in summer. The same happens in Britain: London is on BST from late March to late October, so “GMT” in an August invitation is usually meant loosely as “UK time”.
- Mixing up date formats. The UK writes 06/07/2027 for 6 July; the US reads it as 7 June. Write the month as a word (“6 July 2027”) on international invites.
- 12-hour vs 24-hour clocks. The US mostly uses am/pm, while UK timetables and many workplaces use the 24-hour clock. 12am means midnight and 12pm means noon, which trips up plenty of people; “midnight” and “noon” are clearer.
- Forgetting the date change. Late evening in New York is the early hours of the next day in London, as Example 3 shows.
Frequently asked questions
Is New York 4 or 5 hours behind London?
Five hours for almost all of the year. It is four hours for roughly three weeks in March (after the US changes its clocks and before the UK does) and for about one week from late October to early November (after the UK changes back and before the US does).
When do the clocks change in the UK and the US?
The UK changes on the last Sunday of March and the last Sunday of October. The US changes on the second Sunday of March and the first Sunday of November. In 2027 that means 14 March and 7 November in the US, and 28 March and 31 October in the UK.
What is the best time for a London–New York call?
Between 2pm and 5pm London time (9am to noon in New York) suits most people, because both sides are at work. Mid-afternoon London time is a good default that also leaves room for New York colleagues to arrive and settle in.
Does the Quoteen time zone converter handle daylight saving?
Yes. It applies the official rules for the exact date you enter, so it gives the four-hour answer during the gap weeks and the five-hour answer the rest of the year.
Convert any time in seconds
Doing the sums by hand is a useful check, but for everyday scheduling the quickest route is our free London to New York time zone converter: pick a date and time, choose the two cities, and it shows the matching local time with daylight saving already applied. It also covers Paris, Dubai, Karachi, Tokyo, Sydney and more. To add or subtract hours and minutes within one time zone, try the time calculator, and if you are planning a project across both countries, our guide to how many working days there are in a year in the UK and US shows how bank and federal holidays change the count.