BST stands for British Summer Time. It is UTC+01:00 from UTC — 1 hours ahead of UTC — and it is used in Europe, in London, Edinburgh, Dublin (Ireland uses IST, Irish Standard Time, at the same offset). BST is the summer time of the United Kingdom, in effect from the last Sunday of March to the last Sunday of October. In winter the UK is on GMT (UTC+0).

Try the tool: UTC Converter — convert any time to and from BST, with the offset for the date you choose.

When is BST in effect?

BST is the summer time — the daylight saving time — of its zone. In 2026 it is in effect from Sunday, 29 March 2026 to Sunday, 25 October 2026. Outside those dates, the same places use the standard time instead. The spring change moves the clocks forward one hour — 2am becomes 3am — and the autumn change moves them back — 2am becomes 1am.

What time is it when it is 12:00 BST?

City Local time when it is 12:00 BST (15 January 2026)
New York 6:00 am
London 11:00 am
Paris 12:00 pm
Dubai 3:00 pm
Mumbai 4:30 pm
Tokyo 8:00 pm
Sydney 10:00 pm
Los Angeles 3:00 am

The table is worked out from the offsets: 12:00 BST is 11:00 am UTC, and each city's local time is UTC plus its own offset. The half-hour cities are the ones to watch: Mumbai is 30 minutes past the hour, because India is on UTC+05:30. The UTC converter does this calculation for any city and any date.

BST and GMT

BST is one hour ahead of GMT: when it is 12:00 GMT it is 13:00 BST. GMT is the winter time of the United Kingdom and BST is the summer time, so the two never overlap — a place is on one or the other, never both. The change happens on the last Sunday of March (GMT to BST) and the last Sunday of October (BST to GMT). See what is GMT for the full history.

BST through the year

Whether BST is in effect in each month of 2026, for London:

Month BST in effect? Offset in effect
January No UTC+00:00
February No UTC+00:00
March No UTC+00:00
April Yes UTC+01:00
May Yes UTC+01:00
June Yes UTC+01:00
July Yes UTC+01:00
August Yes UTC+01:00
September Yes UTC+01:00
October Yes UTC+01:00
November No UTC+00:00
December No UTC+00:00

BST is in effect for part of the year and not for the rest — the table shows exactly which months. The change happens on the clock-change dates, not on the first of a month, so a month that straddles a change (March or October/November) is on one offset at the start and the other at the end. The UTC converter shows the offset in effect on any date.

What time is it when it is 09:00 BST?

Nine in the morning is the start of the working day, so it is the time that matters for meetings. When it is 09:00 BST on 15 January 2026, the time in eight major cities is:

City Local time at 09:00 BST
New York 3:00 am
London 8:00 am
Paris 9:00 am
Dubai 12:00 pm
Mumbai 1:30 pm
Tokyo 5:00 pm
Sydney 7:00 pm
Los Angeles 12:00 am

BST and UTC, worked both ways

Converting from BST to UTC: subtract the offset. 09:00 BST is 8:00 am UTC, and 15:00 BST is 2:00 pm UTC. Converting from UTC to BST: add the offset. 12:00 UTC is 1:00 pm BST, and 18:00 UTC is 7:00 pm BST. If the result crosses midnight, the date changes: 12:00 am is the time in BST when it is 23:00 UTC, and if that is past midnight it is the next day. The UTC converter does both directions for any time and any date.

Common mistakes with BST

The commonest mistake is using BST for the wrong season: writing EST in July, when New York is on EDT, or writing EDT in January, when it is on EST. The second mistake is forgetting the place: EST means different things in North America (UTC−05:00) and Australia (UTC+10:00), and CST means different things in North America (UTC−06:00), China (UTC+08:00) and Cuba (UTC−05:00). The fix for both is the same: write the offset with the abbreviation, and check the date. The time zone converter shows the offset for any city on any date, so there is no need to guess.

Frequently asked questions

What does BST stand for?

British Summer Time. It is UTC+01:00 from UTC, and it is used in Europe, in London, Edinburgh, Dublin (Ireland uses IST, Irish Standard Time, at the same offset).

What is the UTC offset of BST?

UTC+01:00. That means BST is 1 hours ahead of UTC: when it is 12:00 UTC it is 1:00 pm BST.

When is BST used?

In summer, during daylight saving — in 2026, from the spring clock change to the autumn clock change. In winter the same places use the standard time instead.

What cities use BST?

London, Edinburgh, Dublin (Ireland uses IST, Irish Standard Time, at the same offset). BST is the summer time of the United Kingdom, in effect from the last Sunday of March to the last Sunday of October. In winter the UK is on GMT (UTC+0).

How do I convert BST to my time?

Convert BST to UTC first — subtract UTC+01:00 — then add your own offset. Or use the UTC converter: enter the time in BST and it gives the time in any city.

Is BST the same as GMT?

No. BST and GMT are the same places in different seasons, one hour apart. BST is UTC+01:00 and GMT is UTC+00:00.

What time is it in BST now?

The UTC converter shows the current time in BST live — it is UTC plus UTC+01:00. Because BST is only in effect for part of the year, the converter shows the offset in effect today, not the one in effect in another season.

Related pages

Sources

  • IANA Time Zone Database, via Node.js Intl (Intl.DateTimeFormat with timeZone) — offsets, daylight saving dates and local times in this article were worked out from the IANA database, not typed from memory.
  • TimeFlow's own time-zone data (data/cities.ts, data/dst.ts), computed from the IANA database.
  • Time zone rules and offsets: the IANA Time Zone Database, as applied by this site's tools. Offsets on this page are computed from the database for the dates stated.
  • TimeFlow's UTC converter and time zone converter — the live tools behind the numbers on this page.
  • Time-zone and daylight saving rules are set by governments and can change. For flights, deadlines and meetings that cannot move, confirm the time with an official source.