Datereckon

BST to GMT

British Summer Time to Greenwich Mean Time, with the offset for today's date rather than an average.

GMT time-1hours

Greenwich Mean Time is behind British Summer Time — noon in BST is 11:00 am in GMT

BST today UTC+01:00
GMT today UTC+00:00
Working-hour overlap 7 h

Convert a specific time from British Summer Time to Greenwich Mean Time
BST (British Summer Time)GMT (Greenwich Mean Time)Working hours in both?
7:00 am 6:00 am No
8:00 am 7:00 am No
9:00 am 8:00 am No
10:00 am 9:00 am Yes
11:00 am 10:00 am Yes
12:00 pm 11:00 am Yes
1:00 pm 12:00 pm Yes
2:00 pm 1:00 pm Yes
3:00 pm 2:00 pm Yes
4:00 pm 3:00 pm Yes
5:00 pm 4:00 pm No
6:00 pm 5:00 pm No
7:00 pm 6:00 pm No
8:00 pm 7:00 pm No

This calculator needs JavaScript to recalculate. Without it you are reading the answer worked out on 28 August 2026, which is exact for that date and does not change by itself. With JavaScript on, the page works the answer out again for the date you open it.

Worked out for · conventions last checked

Which zone this page means. BST means British Summer Time (UTC+1) and also Bangladesh Standard Time (UTC+6). This page means the British zone, which applies from the last Sunday in March to the last Sunday in October; the rest of the year the United Kingdom is on GMT. GMT and UTC are the same offset but not the same thing: GMT is a time zone, UTC is a time standard. The United Kingdom is on GMT in winter and BST (UTC+1) in summer.

BST is ahead of GMT by 1 hours today

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

Other conversions from BST

Common questions

What is the time difference between BST and GMT?
The current offset is shown at the top of this page. It is computed for today's date rather than quoted as an average, because the two regions change their clocks on different dates and the gap is different for a few weeks each year.
Is BST the same as British Summer Time all year?
Not necessarily. Standard time and summer time are separate zones with separate abbreviations, so much of the year the technically correct abbreviation is the daylight one. The page states which is in force on today's date.
When do the clocks change in these zones?
The next change date for each zone is shown in the result panel, along with what the offset becomes afterwards.
What is a good meeting time between BST and GMT?
The business-hours overlap window is shown below the converter. Where there is no overlap the page says so rather than suggesting an impossible time.

Related calculators

This page could not bring itself up to date in your browser, so the dates above are the ones worked out on 28 August 2026. They are exact for that date and do not change by themselves. Enter your own dates in the calculator above for an answer worked out now.