British Summer Time begins2026 · Date · History
GOV.UK states the reusable UK rule: clocks go forward one hour at 1am on the last Sunday in March. UK Parliament material documents William Willett’s campaign and the Summer Time Act 1916 history.
About British Summer Time begins
British Summer Time begins when clocks in the United Kingdom go forward by one hour at 1:00 a.m. on the last Sunday in March.
Because GOV.UK provides a reusable rule, the date can be calculated for future years instead of being treated as an edition-specific refresh.
Why British Summer Time begins matters
The change marks the start of the UK’s summer clock arrangement, moving from Greenwich Mean Time to British Summer Time.
It is a civil time-standard transition, not a bank holiday or public holiday.
History of British Summer Time begins
William Willett promoted a British daylight-saving proposal in the early twentieth century, including his 1907 pamphlet The Waste of Daylight.
Parliament implemented seasonal clock changes through the Summer Time Act 1916 during the First World War.
Parliamentary historical material records the first UK clock advance on May 21, 1916.
Current GOV.UK guidance states that clocks go forward at 1:00 a.m. on the last Sunday in March.
How the observance developed
This timeline uses documented milestones from reviewed sources. Missing stages are left out rather than guessed.
William Willett (UK seasonal-clock campaign)
UK Parliament material identifies Willett as the first in the UK to promote the modern clock-adjustment proposal in 1907.
Parliament of the United Kingdom
Summer Time Act 1916
First documented observance
Parliamentary committee evidence records the first UK clock advance on May 21, 1916.
What the evidence establishes
Confirmed institutional roles and milestones are shown first. Details that could not be established from the reviewed sources are listed separately below.
3 fields not established in reviewed sources
How to Observe British Summer Time begins
Check clocks on devices that do not update automatically.
Confirm travel, transport, work and appointment times around the overnight change.
For systems or international meetings, record time zones explicitly rather than relying on ambiguous local-time labels.
If sleep disruption affects you, plan routine changes conservatively and seek professional advice for persistent health concerns rather than treating a clock-change guide as medical advice.
Use GOV.UK for the current rule and target-year dates.
British Summer Time begins Facts
BST begins on the last Sunday in March.
The UK clock moves forward by one hour at 1:00 a.m.
William Willett was an important UK campaigner for seasonal clock changes.
The Summer Time Act 1916 established the wartime British scheme.
The transition is not a bank holiday or public holiday.
Topic and context
What this page does not assume
- Keep the source-defined country, community, organizer or institutional scope; do not silently broaden it.
- Do not treat the title alone as proof of government recognition or public-holiday status.
- Do not add a creator, founding story or origin claim unless the supporting evidence establishes it.
- Confirm the date again before carrying it into a new year.
Evidence & sources
Sources used across the guide are gathered here. Labels show how each source supports the page, and contextual references are kept separate from primary evidence.
GOV.UK — When do the clocks change? (opens in a new tab)
Government Time Standard Guide
UK Parliament written evidence (opens in a new tab)
UK Parliament — Clock changes: is it time for change? (opens in a new tab)
Parliamentary History
Understand it, compare it, then explore further
Start with the most common factual questions, then compare closely related observances and explore useful connections.
Frequently asked questions
When is British Summer Time begins?
Last Sunday in March; clocks go forward at 1:00 a.m. The documented recurrence rule is: Last Sunday in March.
Does British Summer Time begins fall on the same date every year?
It follows a recurring calendar rule, so the Gregorian date can change from year to year.
Is British Summer Time begins an official public holiday?
The reviewed sources verify it within this scope: United Kingdom. That recognition does not by itself make it a statutory public holiday; the site only makes public-holiday claims when reliable evidence explicitly does so.
Who established or recognizes British Summer Time begins?
The reviewed sources identify Parliament of the United Kingdom as the proclaiming or establishing body. The proposer or originator is recorded separately as William Willett (UK seasonal-clock campaign).
Is British Summer Time begins international or country-specific?
This observance is specific to United Kingdom. Its fuller verified scope is: United Kingdom.
How is this page verified?
The factual information is checked against reviewed sources, including the date pattern, scope and institutional history. This page was checked on 2026-10-08.
When does British Summer Time begin?
At 1:00 a.m. on the last Sunday in March, when UK clocks move forward by one hour.
Does the date need a yearly manual refresh?
No. GOV.UK states a reusable last-Sunday-in-March rule, so the target-year date can be calculated.
When did Britain first use the scheme?
Parliamentary history records the first UK clock advance under the 1916 scheme on May 21, 1916.
Who promoted the idea in Britain?
William Willett was the leading early British campaigner, publishing The Waste of Daylight in 1907.
Is the start of BST a public holiday?
No. It is a time-standard transition, not a bank holiday or public holiday.
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