New York and London are the default transatlantic pair for a reason: the overlap is real, daily, and wide enough for an actual conversation. It is also the pair people get sloppy with, because “everyone knows” it is five hours. Everyone does not know the two weeks in March 2026 when it is four hours while Britain is still on GMT, or the late-October week when Britain has already gone back and New York has not.
Open the New York–London planner when you book anything that will still exist after a DST weekend. The folklore is not a timezone.
The ordinary year
For most of 2026 the offset is:
- Winter (both standard): New York UTC−5, London UTC+0 → five hours. 09:00 ET is 14:00 GMT. - Summer (both daylight): New York UTC−4, London UTC+1 → five hours. 09:00 EDT is 14:00 BST.
The offset returning to five hours in summer is why teams get complacent. The *local* hours of the overlap still shift because both cities move, and because London’s polite end of day is earlier than New York’s.
A London desk that protects 17:30 leaving time will not take your 13:00 ET “quick sync.” That is 18:00 BST. The overlap that respects both cultures is New York morning / London early-to-mid afternoon.
Practical default: 09:30–12:00 ET / 14:30–17:00 UK in ordinary weeks. If the London side is in finance, you can start closer to 09:00 ET / 14:00 UK. If the London side is a product team that actually leaves on time, stop proposing 12:30 ET.
The 2026 shoulder weeks
Write these on a sticky note:
1. 8 March 2026 — US DST begins. Until 29 March, New York is on EDT and London is still on GMT. Offset is four hours. 09:00 ET is 13:00 GMT, not 14:00. 2. 29 March 2026 — UK DST begins. Offset returns to five. 3. 25 October 2026 — UK DST ends. Until 1 November, London is on GMT and New York is still on EDT. Offset is four hours again. 4. 1 November 2026 — US DST ends. Offset returns to five.
If your repeating weekly standup was created in February and never reviewed, the first Monday after 8 March will surprise someone. The invite did not lie; your brain reused last month’s conversion.
Who should wake up?
Neither side, if you can help it. New York has more morning than London has evening. Asking London to stay until 19:00 so New York can “just finish standup” is how you lose the Londoners to companies that can tell time. Asking New York to meet at 07:00 ET every week is how you lose the New Yorkers to the same.
Rotate the pain only when a third city — Dublin, Berlin, or a West Coast office — forces it. A New York–London pair does not need 07:00 heroes.
Etiquette inside the window
Even inside 09:30–12:00 ET, a Slack mention is not a meeting. London lunch still exists; it is just shorter and earlier than Paris. Friday after 16:00 UK is already the weekend in a way Manhattan pretends not to notice. Bank holidays in England, Wales, Scotland, and Northern Ireland do not match US federal holidays. Check both calendars before you assume a Monday is a workday.
If you are writing after hours, schedule send to 09:30 in *their* city, not yours. A 23:00 ET message that lands at 04:00 in London does not become kind because you were “just finishing up.”
A worked Tuesday in June 2026
Suppose you sit in New York and need thirty minutes with a product manager in Shoreditch. You propose 10:00 ET. Their calendar shows 15:00 BST. That is inside both windows. You title the hold `NY 10:00 ET / LDN 15:00 BST` and paste the pair link in the description so a later-joining exec can check the offset without pinging you. You do not add a “quick pre-sync” at 09:00 ET the same day; that is 14:00 in London and will cannibalize their deep-work block after lunch.
If the same meeting slips to 13:00 ET, you have left the overlap. London is commuting. Reschedule rather than “just this once,” because just this once becomes the weekly slot.
Finance desks on both sides can go later. That is a contract, not a culture you should copy into a design team. If you do not know which you are dealing with, assume 17:30 UK is the wall.
When a third city joins
Add Dublin and the clocks stay friendly with London. Add Berlin and you are still in Central European afternoon while New York is in morning. Add San Francisco and the overlap collapses: the Londoners would have to stay late or the New Yorkers would have to split into two meetings. Split them. A three-continent standup that makes one person attend at 07:00 and another at 19:00 is not inclusion; it is arithmetic denial.
The pair is easy on purpose. Treat it that way. Book the overlap, name both times in the title, and open New York–London whenever a DST weekend is within two weeks of the meeting.