About this site

britishsummertime.co.uk is an independent reference site explaining British Summer Time, the UK clock changes, and how UK time relates to the rest of the world. We are not a government body and have no affiliation with any official timekeeper.

How we keep this accurate. UK clock-change dates are calculated directly from the rule set out in the Summer Time Order 2002 (last Sunday of March and October), so they are fixed years in advance. Our world clock and converter read the IANA time-zone database built into your own browser and device, which is maintained continuously — that is why the live tools stay correct through every daylight saving change, including recent rule changes such as British Columbia’s move to permanent daylight saving time in 2026.

Where we state historical or scientific facts, we cite primary and authoritative sources (legislation.gov.uk, GOV.UK, the National Physical Laboratory, the Royal Observatory Greenwich and peer-reviewed research). See any guide’s “Sources” section for references.

This site is supported by advertising. Adverts never influence the facts we publish.

Questions or corrections? Contact us.