What BST means: UK daylight saving at UTC+1
The UK shifts to UTC+1 every summer. This seasonal offset is British Summer Time, and it pushes the base standard, Greenwich Mean Time (GMT), forward by exactly one hour.
The legal basis is the Summer Time Act 1972, which defines the BST period. The dates are fixed by the Summer Time Order 2002, which implemented the EU-wide DST harmonisation and remains in force after Brexit.
BST start and end dates
BST begins on the last Sunday of March at 01:00 UTC. Clocks go forward 60 minutes: 01:00 GMT becomes 02:00 BST. BST ends on the last Sunday of October at 02:00 BST. Clocks go back 60 minutes: 02:00 BST becomes 01:00 GMT.
| Event | Date | Local time (before) | Local time (after) |
|---|---|---|---|
| BST starts 2026 | Sunday 29 March | 01:00 GMT → 02:00 BST | |
| BST ends 2026 | Sunday 25 October | 02:00 BST → 01:00 GMT | |
| BST starts 2027 | Sunday 28 March | 01:00 GMT → 02:00 BST | |
| BST ends 2027 | Sunday 31 October | 02:00 BST → 01:00 GMT |
The change always happens at 01:00 UTC to minimise disruption. Pubs have closed. Most rail services have not started. The clock change schedule is the same every year.
BST vs GMT: the annual switch
In winter, the UK uses GMT (UTC+0). In summer, it uses BST (UTC+1). The difference is exactly one hour. When London is on BST, Paris (CEST, UTC+2) is one hour ahead, and New York (EDT, UTC-4) is five hours behind. In winter, Paris (CET, UTC+1) is still one hour ahead, and New York (EST, UTC-5) is five hours behind.
The switch reverses the relationship with cities that do not observe DST. In January, when London is on GMT, Dubai (UTC+4) is four hours ahead. In July, when London is on BST, Dubai (UTC+4) is three hours ahead.
Is BST the same as other summer times?
Yes, BST shares its clock time with two other legal time zones:
- Irish Standard Time (IST), Republic of Ireland uses IST (UTC+1) in summer and GMT in winter. Same clocks, different name.
- Western European Summer Time (WEST), Portugal, the Canary Islands (Spain), and the Faroe Islands use WEST (UTC+1) on the same dates.
BST is one hour behind Central European Summer Time (CEST). When it is 12:00 BST in London, it is 13:00 CEST in Paris, Berlin, and Rome.
What BST means for your day
During BST, London's daylight shifts later. On the June solstice (21 June 2026), sunrise is at 04:42 and sunset at 21:21: 16 hours 39 minutes of daylight. On the September equinox (22 September 2026), sunrise is at 06:44 and sunset at 19:01: 12 hours 17 minutes.
The longer evenings affect business hours, transport schedules, and school runs. The London Stock Exchange opens at 08:00 BST (07:00 GMT). UK business hours stay the same on the clock, but the usable daylight shifts.