BST to GMT Time Converter

When it is 9:00 AM BST, it is 9:00 AM GMT. Greenwich Mean Time (GMT, UTC+0) is 1 hour behind British Summer Time (BST, UTC+1). Your working-hours overlap window is 10:00 AM–5:00 PM BST (9:00 AM–4:00 PM GMT).

BST to GMT Conversion Table

Major Cities Using BST and GMT

British Summer Time (BST): London, Manchester, Dublin, Edinburgh.

Greenwich Mean Time (GMT): London, Manchester, Dublin, Edinburgh.

How many hours between BST and GMT?

BST is UTC+1 and GMT is UTC+0, a difference of 1 hour. GMT is behind BST. This difference can shift by an hour in either direction during Daylight Saving Time transitions — if one zone observes DST and the other doesn't, the offset narrows or widens for part of the year.

Business Hours Overlap: BST ↔ GMT

Assuming a 9:00 AM – 5:00 PM workday on each side, your working-hours overlap window is 10:00 am–5:00 pm bst (9:00 am–4:00 pm gmt). To visualize this instantly for any pair of cities, use the visual meeting planner or the timezone overlap finder — both highlight the green overlap window on a live timeline.

Does BST observe Daylight Saving Time?

British Summer Time (BST) is based on the Europe/London IANA timezone. DST observance depends on the jurisdiction — for example, most of the continental US switches between standard and daylight time, while India, Japan, and most of Southeast Asia do not observe DST at all. WorldClock.lol uses the authoritative IANA timezone database, so every conversion automatically accounts for the correct DST rules on the date you're converting.

When is 9 AM BST in GMT?

When it is 9:00 AM in British Summer Time (BST, UTC+1), it is 9:00 AM in Greenwich Mean Time (GMT). For other times of day, scan the conversion table above or drop into the interactive converter to pick an exact minute. The converter handles both standard and daylight variants correctly.

How to Use This BST to GMT Converter

1. Type or drag any time in the BST input above — the GMT equivalent updates instantly.
2. Check the day indicator. When the converted time crosses midnight, the tool shows +1 day or −1 day so you don't book a meeting on the wrong date.
3. Copy the shareable URL to send the specific conversion to a colleague — the link preserves your exact selection.
4. Switch directions by swapping the input zones, or open GMT to BST for the reverse.

Related BST Converters

• BST to EST
• BST to PST
• BST to UTC
• BST to IST
• BST to JST
• BST to CET

Related GMT Converters

• EST to GMT
• PST to GMT
• UTC to GMT
• IST to GMT
• JST to GMT
• CET to GMT

More Time Tools

• All Time Zone Converters — browse every supported pair
• About BST (British Summer Time) — current time, cities, DST rules
• About GMT (Greenwich Mean Time) — current time, cities, DST rules
• Meeting Planner — find the best time for a multi-city meeting
• Best Time to Call — optimal calling windows between any two cities
• UTC Time Now — the reference point for every conversion
• DST Schedule 2026 — every daylight-saving transition this year