How daylight saving time moves your meeting overlap
Working hours stay fixed on local clocks, but UTC offsets change twice a year. When two places switch on different dates, their shared window moves, and a recurring meeting set in one zone lands at a different local time in the other.
Worked example
- Date
- March 4, 2026
- Working hours
- America/New_York · 09:00–17:00Europe/London · 09:00–17:00
- Shared window (UTC)
- 14:00–17:00 UTC
- Overlap
- 3 hours
- Local times
- America/New_York · 09:00–12:00 (UTC−05:00)Europe/London · 14:00–17:00 (UTC+00:00)
- 10:00 meeting in America/New_York
- Europe/London · 15:00–15:30 (UTC+00:00)
- Date
- March 18, 2026
- Working hours
- America/New_York · 09:00–17:00Europe/London · 09:00–17:00
- Shared window (UTC)
- 13:00–17:00 UTC
- Overlap
- 4 hours
- Local times
- America/New_York · 09:00–13:00 (UTC−04:00)Europe/London · 13:00–17:00 (UTC+00:00)
- 10:00 meeting in America/New_York
- Europe/London · 14:00–14:30 (UTC+00:00)
- Date
- April 1, 2026
- Working hours
- America/New_York · 09:00–17:00Europe/London · 09:00–17:00
- Shared window (UTC)
- 13:00–16:00 UTC
- Overlap
- 3 hours
- Local times
- America/New_York · 09:00–12:00 (UTC−04:00)Europe/London · 14:00–17:00 (UTC+01:00)
- 10:00 meeting in America/New_York
- Europe/London · 15:00–15:30 (UTC+01:00)
- Date
- October 28, 2026
- Working hours
- America/New_York · 09:00–17:00Europe/London · 09:00–17:00
- Shared window (UTC)
- 13:00–17:00 UTC
- Overlap
- 4 hours
- Local times
- America/New_York · 09:00–13:00 (UTC−04:00)Europe/London · 13:00–17:00 (UTC+00:00)
- 10:00 meeting in America/New_York
- Europe/London · 14:00–14:30 (UTC+00:00)
On the day the clocks change
America/New_York: clocks skip 60 minutes. Missing times are excluded.
- Date
- March 8, 2026
- Shared window (UTC)
- 13:00–17:00 UTC
- Overlap
- 4 hours
- Local times
- America/New_York · 09:00–13:00 (UTC−04:00)Europe/London · 13:00–17:00 (UTC+00:00)
How it works
- In 2026 the US changes clocks on 8 March and 1 November; the UK changes on 29 March and 25 October. Between those dates, New York is 4 hours behind London instead of 5.
- During those weeks, a 10:00 meeting in New York starts at 14:00 in London instead of 15:00. Calendar events keep the organizer's zone, so attendees elsewhere see the shift.
- On the change day itself, some local times are skipped or repeated. The planner works with real instants, excludes times that do not exist, and shows the UTC offset for times that occur twice.
Calculations and calendar files are made in your browser. No calendar account is connected.