BST to UTC

BST is ahead of UTC by 1 hours today

On 28 August 2026, British Summer Time is on BST at UTC+01:00 and Coordinated Universal Time is on UTC at UTC+00:00. The gap between them is 1 hours, with UTC behind. So 9:00 am in BST is 8:00 am in UTC, and 5:00 pm in BST is 4:00 pm in UTC. Going the other way, see UTC to BST.

The gap is not constant, and that is the part that catches people out

British Summer Time is currently observing daylight saving and changes next on 25 October 2026, when clocks go back an hour. Coordinated Universal Time does not observe daylight saving at all, so the whole of the seasonal change comes from the BST side: the gap moves by an hour twice a year even though nothing changes in Coordinated Universal Time.

When you can actually both be at work

Taking a working day as 9:00 am to 5:00 pm local at each end, there are 7 overlapping hours in a normal day. In BST that window runs from 10:00 am to 5:00 pm, which is 9:00 am to 4:00 pm in UTC. Anything outside it needs one side to start early or finish late.

Zone rules are set by legislation and change, sometimes at short notice. This page is built against tzdata 2026a, last reviewed 2026-08-18. Quarterly. Zone rules change by legislation, sometimes at short notice. Version and review date are shown on every zone page. The converter above reads your browser's own copy of the zone database, so if a rule has changed since this page was built the live answer follows the new rule — and so does everything above, which is worked out from the same database when you open the page.

Every convention used above — whether the start date counts, how month ends are clamped, which holidays close an office — is written out on the methodology page, including the daylight-saving rules behind the 1-hour gap above.