GMT to BST
+1hGMT
GMTSOURCEBST
BSTGreen rows indicate typical business hours (9 AM - 5 PM)
GMT and BST on the World Map
The map below highlights the GMT (Greenwich Mean Time) and BST (British Summer Time) timezone regions across the globe.
GMT – Greenwich Mean Time
UTC+00:00Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London. It is the same as UTC+00:00.
- •GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London.
- •The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
- •GMT and UTC are often used interchangeably, but UTC is based on atomic clocks.
- •Iceland uses GMT year-round and never observes daylight saving time.
- •The UK switches from GMT to BST (British Summer Time) in late March each year.
BST – British Summer Time
UTC+01:00British Summer Time (BST, UTC+01:00) is the daylight saving period in the United Kingdom, running from late March to late October.
- •BST runs from the last Sunday in March to the last Sunday in October.
- •BST is exactly one hour ahead of GMT, the UK's standard time.
- •During BST, London is 4 hours ahead of New York while the US is on Eastern Daylight Time.
- •The Isle of Man and the Channel Islands also observe BST.
GMT to BST Time Difference – Complete Guide
GMT runs on Greenwich Mean Time (GMT) at UTC+00:00. BST runs on British Summer Time (BST) at UTC+01:00. That puts GMT 1 hour ahead of BST — a difference of +1h at the current offsets.
In practice, when it is 9:00 AM in GMT it is 10:00 AM in BST. Midnight in GMT is 1:00 AM in BST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
GMT to BST time conversion table
| GMT (GMT) | BST (BST) | Day |
|---|---|---|
| 12:00 AM | 1:00 AM | same day |
| 6:00 AM | 7:00 AM | same day |
| 7:00 AM | 8:00 AM | same day |
| 8:00 AM | 9:00 AM | same day |
| 9:00 AM | 10:00 AM | same day |
| 12:00 PM | 1:00 PM | same day |
| 3:00 PM | 4:00 PM | same day |
| 5:00 PM | 6:00 PM | same day |
| 6:00 PM | 7:00 PM | same day |
| 9:00 PM | 10:00 PM | same day |
Why people convert GMT to BST time
- Scheduling a call from GMT to BST: a 10:00 AM start in GMT lands at 11:00 AM in BST, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both GMT and BST are inside the 9-to-5 working day between 9:00 AM and 4:00 PM GMT time (10:00 AM–5:00 PM BST). That is roughly 7 hours of usable overlap.
- Watching a live event or market open: GMT viewers need 10:00 AM in BST to catch a 9:00 AM start there, and 11:00 PM if the event is anchored to GMT.
- Always state the zone abbreviation, not just the hour. "3:00 PM GMT" is unambiguous; "3 PM" across a +1h gap is not.
- Block 9:00 AM–4:00 PM GMT as the recurring meeting window if you work primarily from GMT and need BST colleagues present.
About GMT (Greenwich Mean Time)
Greenwich Mean Time (GMT) is the clock time at the Royal Observatory in Greenwich, London, which sits on the Prime Meridian (0° longitude). GMT serves as the reference point from which all other time zones are calculated. The United Kingdom uses GMT during winter months and switches to British Summer Time (BST, UTC+01:00) from late March to late October. Several West African nations use GMT year-round. GMT is often used interchangeably with UTC (Coordinated Universal Time), although technically they are different – UTC is based on atomic clocks while GMT is based on Earth's rotation.
About BST (British Summer Time)
British Summer Time (BST) is the daylight saving period in the United Kingdom, when clocks move one hour forward from Greenwich Mean Time (GMT, UTC+00:00) to UTC+01:00. It runs from the last Sunday in March to the last Sunday in October. England, Scotland, Wales and Northern Ireland all follow it, along with the Isle of Man and the Channel Islands of Jersey and Guernsey. During BST, London is one hour ahead of UTC, four hours ahead of New York on Eastern Daylight Time, and five hours ahead of New York once the United States returns to Eastern Standard Time in November. BST is also used to abbreviate Bangladesh Standard Time (UTC+06:00), which is listed separately on this site.
Best time to call between GMT and BST
Both GMT and BST sit inside the 9 AM – 5 PM working day between 9:00 AM–4:00 PM GMT, which is 10:00 AM–5:00 PM BST. That gives roughly 7 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
GMT and BST share 7 hours of working-hours overlap (9:00 AM–4:00 PM GMT), so scheduling a live meeting is straightforward.
GMT is 1 hour ahead of BST (GMT UTC+00:00 → BST UTC+01:00). The shared working window is 9:00 AM–4:00 PM GMT. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
GMT
☀ Currently in DST
Standard: UTC+00:00 · DST: UTC+01:00
Clocks fall back on Sun, Oct 25, 2026
BST
☀ Currently in DST
Standard: UTC+00:00 · DST: UTC+01:00
Clocks fall back on Sun, Oct 25, 2026
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between GMT and BST?
GMT (GMT, UTC+00:00) is 1 hour ahead of BST (BST, UTC+01:00). The gap is currently +1h.
How do I convert GMT time to BST time?
Add +1h to GMT local time. For example, 9:00 AM in GMT is 10:00 AM in BST.
What time is it in BST right now?
BST uses BST at UTC+01:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +1h offset from GMT.
What is the best time to call BST from GMT?
Call between 9:00 AM and 4:00 PM GMT — that maps to 10:00 AM–5:00 PM BST and keeps both parties inside the working day.
Which is ahead, GMT or BST?
GMT is 1 hour ahead of BST. When it is 12:00 PM in GMT it is 1:00 PM in BST.
Does daylight saving time affect the GMT–BST difference?
Neither zone observes daylight saving time, so the +1h offset between GMT and BST is fixed all year.
Which other cities share GMT's time zone?
GMT also covers London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar and 5 more.
Which countries use GMT, GMT's zone?
GMT is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, Mali, Mauritania and 7 more.
Is there a day difference between GMT and BST?
Not normally. The +1h gap only pushes the date over for late-evening times.
What is the time difference between GMT and BST?
BST is +1h from GMT.
What timezone is GMT in?
GMT operates on its local timezone.
What timezone is BST in?
BST operates on its local timezone.
Which countries use GMT (Greenwich Mean Time)?
GMT is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, and 9 more countries.
Does GMT observe daylight saving time?
Yes, GMT switches to BST during summer months.
What are some interesting facts about GMT?
GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London. The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
Which cities are in the BST timezone?
Major cities in the BST timezone include London, Birmingham, Manchester, Glasgow, Edinburgh, Cardiff, Belfast, Liverpool.
What is the UTC offset for BST?
British Summer Time (BST) is at UTC+01:00. During daylight saving time, it shifts to BST.
What should I know about the BST timezone?
BST runs from the last Sunday in March to the last Sunday in October. BST is exactly one hour ahead of GMT, the UK's standard time.
When is it midnight in GMT, what time is it in BST?
When it is 12:00 AM (midnight) in GMT (GMT), it is +1h later in BST (BST).
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See every conversion from GMT →·See every conversion from BST →