Timezone Q&A
Does London change daylight-saving time?
Yes. London uses GMT in winter and BST in summer. That seasonal shift can change the practical meeting overlap with US teams for short periods each year.
GMT and BST
GMT is the winter offset. BST is one hour ahead of GMT during the UK daylight-saving season, so London local time is not the same fixed offset all year.
Why teams get caught
The UK and US switch on different dates, so standing meetings can temporarily move by an hour for one side.
How to prevent mistakes
Schedule from the actual date and city pair instead of relying only on a memorized offset.
What to check for US meetings
London and US cities do not always change clocks on the same dates. During those short transition periods, a standing call can move by one hour for one side. Check the exact date, then write both London time and the US local time in the invite so attendees can spot the shift.
Examples
- London uses GMT in winter and BST in summer.
- US and UK clock changes do not always happen on the same weekend.
Before you send it
- Review recurring US-UK meetings around March and October.
- Use London as the location instead of hard-coding GMT year-round.
- Confirm the exact date when an invite is near a clock change.
- If a meeting is described as GMT in summer, ask whether the organizer really means London local time.
- When coordinating with US teams, test the same local time across the next clock-change weekend.
- For public events, write London time plus the UTC offset so international readers can verify it.