For One Week Every Fall, London and New York Are Only 4 Hours Apart (Not 5) — Here's Why
Every October, my team's 2 PM London stand-up quietly turns into a 1 PM meeting for our New York office — and every October, at least one person joins an hour late convinced their calendar app is broken. Nobody changed the invite. Nobody made a mistake. For exactly one week, the United Kingdom and the United States are running on a different time difference than the other 51 weeks of the year, and almost no one schedules around it.
This isn't a glitch. It's the predictable result of two countries ending Daylight Saving Time on different Sundays — and in 2026, that gap runs from October 25 through November 1. If you work with anyone overseas, that week is coming for your calendar too.
What Actually Happens During the Gap Week
Daylight Saving Time (DST) is the practice of setting clocks forward by one hour in spring and back by one hour in autumn, shifting an hour of daylight from morning to evening. Not every country observes it, and the countries that do rarely end it on the same date.
In 2026, the United Kingdom and the European Union end DST on Sunday, October 25, falling back from BST/CEST to GMT/CET. The United States doesn't fall back until Sunday, November 1 — the first Sunday in November, under the federal Uniform Time Act of 1966 (as amended by the Energy Policy Act of 2005). That's a seven-day window where the UK has already "sprung back" and the US hasn't.
Key Takeaway
London and New York are normally 5 hours apart (London ahead). From October 25 to November 1, 2026, that gap temporarily shrinks to 4 hours, because the UK has already moved to GMT while the US East Coast is still on Eastern Daylight Time. The same shift hits any US–UK, US–EU, or US–Ireland meeting scheduled that week.
The reverse happens every spring: the EU and UK spring forward on the last Sunday in March, while the US doesn't spring forward until the second Sunday in March — so the US actually jumps first, briefly widening the gap for about two weeks before the UK catches up.
The Math: Calculating a Meeting Time During the Gap
Here's the formula behind every time zone conversion, gap week or not:
Normally, New York (UTC-4 during EDT) and London (UTC+1 during BST) are 5 hours apart. Say your recurring stand-up is set for 9:00 AM New York time. Before October 25, that's 2:00 PM in London (9 AM + 5 hours). After October 25 but before November 1, London has moved to GMT (UTC+0) while New York is still on EDT (UTC-4) — a 4-hour gap — so that same 9:00 AM New York meeting now lands at 1:00 PM London time, not 2:00 PM. Nothing about the New York side moved; the London side's offset changed underneath it.
Worked the other way: a meeting fixed at 2:00 PM UK time would land at 9:00 AM in New York before the 25th, and 10:00 AM in New York during the gap week — because from New York's perspective, London's clock effectively moved an hour earlier relative to UTC while New York stood still.
⚠️ Note
Most calendar apps (Google Calendar, Outlook) correctly auto-adjust invites created natively in the app, because they store the meeting's UTC moment and each attendee's local time zone separately. The failure case is meetings pasted into a chat message as plain text ("let's do 9am EST / 2pm GMT every Tuesday") — that hardcoded offset silently goes stale the moment either country's clocks change.
Rather than tracking eight different countries' clock-change dates in your head, a time zone converter does this calculation for the exact date you need — it uses the browser's Internationalization API to apply the correct DST rule for that specific day, not just a generic offset.
Why Do Countries Change Clocks on Different Dates?
There's no single global authority that sets Daylight Saving Time — each country or bloc legislates its own start and end dates, which is exactly why the mismatches happen.
- United States: DST runs from the second Sunday in March to the first Sunday in November, set by the Uniform Time Act of 1966 and extended by the Energy Policy Act of 2005.
- European Union & United Kingdom: DST runs from the last Sunday in March to the last Sunday in October, under EU Directive 2000/84/EC (the UK retained the same dates post-Brexit).
- Australia: Only some states observe DST (New South Wales, Victoria, South Australia, Tasmania, ACT), and because Australia is in the Southern Hemisphere, its clocks move in the opposite direction — springing forward on the first Sunday in October and falling back on the first Sunday in April.
- Most of Asia, Africa, and equatorial regions: No DST at all — Japan, China, India, and most of Africa keep a single offset year-round, since daylight hours don't vary enough near the equator to justify the disruption.
The IANA Time Zone Database (also called tz database or zoneinfo) is the reference dataset that operating systems, browsers, and programming languages actually use to track every region's current and historical DST rules. It's maintained by volunteers and updated whenever a government changes its time zone law — which is more often than most people realize.
The Global DST Calendar for Fall 2026
| Region | Clocks Change | Direction | New Offset from UTC |
|---|---|---|---|
| Australia (NSW, VIC, SA, TAS) | Oct 4, 2026 | Forward (spring) | UTC+11 (AEDT) |
| UK & EU | Oct 25, 2026 | Back (fall) | UTC+0 / UTC+1 |
| United States & Canada | Nov 1, 2026 | Back (fall) | UTC-5 to UTC-8 |
| Japan, China, most of Asia | No change | — | Fixed year-round |
Notice Australia moves in the opposite direction entirely — while the UK and US are both falling back into winter time in late October and early November, Sydney and Melbourne are springing forward into daylight time. For a three-way meeting between New York, London, and Sydney scheduled across late September through early November 2026, the time difference shifts twice in six weeks, in two different directions.
💡 Pro Tip
If you manage a recurring deadline or contract term that spans a DST boundary — "payment due 30 business days from signing," say — count the actual business days rather than assuming a flat number of calendar weeks. A business days countdown calculator accounts for weekends without needing you to separately track which side of a clock change the deadline falls on, since business-day counting is time-zone-offset independent.
How to Never Get Caught Out Again
A few habits fix this permanently:
- Store recurring meetings in your calendar app, not a text message. Google Calendar and Outlook both track the attendee's actual time zone and recalculate on the fly — a plain-text "9am EST" pasted in Slack does not.
- Default to UTC for anything technical. Server logs, API timestamps, and cross-team documentation should record the UTC moment, not a local time with an assumed offset. A Unix timestamp converter converts any UTC date and time into the raw epoch seconds your systems actually store, which sidesteps the DST question entirely — a Unix timestamp represents one fixed instant no matter which country's clocks move around it.
- Check the actual date, not just "next Tuesday." If a meeting or deadline falls within seven days of a known DST change, use a date difference calculator to confirm exactly how many days out it is from today, then check whether either party's clock-change date falls in between.
- Re-verify recurring international meetings twice a year — once in early March, once in mid-October — rather than assuming last year's converted time still holds.
Frequently Asked Questions
Why don't the US and UK just change their clocks on the same day?
Each country sets its own Daylight Saving Time law independently — there's no international treaty coordinating the dates. The US follows the Uniform Time Act of 1966 (as amended in 2005), while the UK and EU follow EU Directive 2000/84/EC. The two laws were written decades apart by different governments with no obligation to align.
Does this gap week happen every year, or only in 2026?
It happens every single year, because the US always falls back on the first Sunday in November while the UK and EU always fall back on the last Sunday in October — and those two Sundays are never the same date. The exact gap runs anywhere from one to two weeks depending on how the calendar falls that year.
Which countries don't observe Daylight Saving Time at all?
Most countries near the equator skip DST because day length barely changes across seasons there — this includes Japan, China, India, Indonesia, and the majority of Africa. Within the US, Arizona (outside the Navajo Nation) and Hawaii also opt out and stay on a fixed offset year-round.
How do I know if my calendar invite already accounts for this?
Open the meeting in Google Calendar or Outlook and check that each attendee's time is shown in their own local time zone (not a single fixed time for everyone). If it shows one time for the whole group, the app is storing a UTC moment and converting it correctly per attendee — if it was typed as plain text instead, it won't auto-adjust when either side's clocks change.
Is Daylight Saving Time being abolished?
Various proposals have circulated in both the US Congress and the European Parliament to end the twice-yearly clock change, but as of 2026 none have been fully enacted — both regions continue to observe DST on their existing schedules. Any future change would need to be confirmed against each government's current law rather than assumed.
Try It Yourself
The next time an international meeting feels like it moved by an hour for no reason, it's almost certainly a DST boundary, not a mistake on either end. Plug the exact date into our time zone converter to get the correct conversion for that specific day, use the business days countdown calculator for deadlines that span a clock change, and lean on the Unix timestamp converter whenever you need a time zone-proof way to record exactly when something happened.
