Compare BST vs GMT
See the current time difference between British Summer Time and Greenwich Mean Time, including DST changes and best hours to schedule.
BST and GMT Difference
British Summer Time is UTC+1 while Greenwich Mean Time is UTC+0, so BST is 1 hour ahead of GMT. View the live offset and hour-by-hour comparison table.
DST Changes and Effects
BST is the daylight saving time version used in the UK, while GMT is standard time at UTC+0. This page tracks seasonal clock changes automatically using the IANA timezone database.
Best Meeting Time Windows
Find the most practical meeting hours between British Summer Time and Greenwich Mean Time with a visual scheduling grid. Export selected times to ICS, Google Calendar, or Gmail.
BST (British Summer Time, UTC+1) is 1 hour ahead of GMT (Greenwich Mean Time, UTC+0), so 9:00 BST = 8:00 GMT and 18:00 BST = 17:00 GMT.
Looking for Bangladesh Standard Time? See /time-converter/bst-bangladesh-time-zone.
Looking for Bougainville Standard Time? See /time-converter/bst-bougainville-time-zone.
How to Find the Time Difference Between BST and GMT
Open the BST vs GMT converter: Visit
https://www.xconvert.com/time-converter/bst-vs-gmtto see British Summer Time and Greenwich Mean Time already loaded in the visual comparison grid. This view is useful when you are planning a call with a client in the United Kingdom, coordinating a media deadline tied to London time, or comparing summer scheduling against standard time.Add comparison cities if your schedule includes more regions: Click + Add City and search for places that commonly connect with British Summer Time or Greenwich Mean Time workflows, such as London, Dublin, or Accra. This helps remote teams in finance, logistics, customer support, and government operations compare whether a meeting anchored in British Summer Time will also fit colleagues working on Greenwich Mean Time in West Africa or the British Isles.
Drag across the grid to select a meeting window: Click Select if needed, then drag across the colored timeline on the British Summer Time row to highlight a range in purple, such as 9:00 to 12:00 BST. The grid immediately shows the matching Greenwich Mean Time hours as 8:00 to 11:00 GMT, which is useful for confirming that a London morning session starts one hour earlier for teams following Greenwich Mean Time.
Move, resize, and export the selected slot: Drag the center of the purple selection to shift the entire range, or use the left and right handles to tighten the window before sharing it. Once selected, you can export with ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link, which is practical for sending a confirmed handoff time to a distributed team so each person receives the correct local reference.
BST vs GMT Offset Explained
British Summer Time is UTC+1, while Greenwich Mean Time is UTC+0. That means GMT is 1 hour behind British Summer Time, or equivalently, British Summer Time is 1 hour ahead of Greenwich Mean Time.
British Summer Time is the daylight saving time abbreviation, and its standard counterpart is Greenwich Mean Time. Greenwich Mean Time is the standard-time abbreviation, and its daylight saving counterpart is British Summer Time, so the difference matters most when the United Kingdom, Guernsey, Jersey, and the Isle of Man are observing summer time rather than standard time.
In practical scheduling terms, a meeting set for 9:00 BST happens at 8:00 GMT, 12:00 BST happens at 11:00 GMT, 15:00 BST happens at 14:00 GMT, and 18:00 BST happens at 17:00 GMT. This one-hour shift is especially important for broadcast schedules, travel itineraries, customer support coverage, and cross-border operations involving the United Kingdom and GMT-using countries such as Ghana, Iceland, Senegal, and Ireland.
Where BST and GMT Are Used
British Summer Time is used in Guernsey, Isle of Man, Jersey, and the United Kingdom. This makes it the relevant summer clock reference for London-based business, UK aviation and rail timetables, and seasonal scheduling for organizations operating across the British Isles.
Greenwich Mean Time is used in Burkina Faso, Gambia, Ghana, Guernsey, Guinea, Guinea-Bissau, Iceland, Ireland, Isle of Man, Ivory Coast, Jersey, Liberia, Mali, Mauritania, Saint Helena, Sao Tome and Principe, Senegal, Sierra Leone, Togo, and the United Kingdom. Because GMT spans both parts of the British Isles and multiple West African countries, it appears frequently in shipping, government coordination, nonprofit work, and international customer service teams that need a stable UTC+0 reference.
When the BST vs GMT Difference Matters Most
British Summer Time and Greenwich Mean Time differ by only one hour, but that hour can affect daily operations in industries that run on fixed deadlines. A newsroom publishing at 12:00 BST is working to 11:00 GMT, and a support team covering until 18:00 BST is effectively available until 17:00 GMT for customers using Greenwich Mean Time.
The comparison is also useful for travel planning and transport coordination. If an itinerary, event ticket, or webinar announcement uses Greenwich Mean Time while your office calendar is set to British Summer Time, the visual grid helps prevent arriving an hour early or late, especially for same-day bookings, airport pickups, and virtual events involving the United Kingdom and GMT regions.
Frequently Asked Questions
What is the time difference between British Summer Time and Greenwich Mean Time?
British Summer Time is 1 hour ahead of Greenwich Mean Time. In UTC terms, British Summer Time is UTC+1 and Greenwich Mean Time is UTC+0, so when it is 15:00 BST, it is 14:00 GMT.
Is GMT behind BST or ahead of BST?
Greenwich Mean Time is behind British Summer Time by 1 hour. This means a work block scheduled at 9:00 to 12:00 BST corresponds to 8:00 to 11:00 GMT, which is important when teams share calendars but use different time labels.
Is BST British Summer Time or Bangladesh Standard Time?
On this page, BST means British Summer Time, which is UTC+1. BST can also mean Bangladesh Standard Time, which is UTC+6, and that separate meaning is covered at /time-converter/bst-bangladesh-time-zone; Bougainville Standard Time is another separate meaning at /time-converter/bst-bougainville-time-zone.
Why are BST and GMT different if both are used in the United Kingdom?
British Summer Time is the daylight saving time abbreviation, while Greenwich Mean Time is the standard-time abbreviation. The United Kingdom uses British Summer Time for summer scheduling and Greenwich Mean Time as the standard counterpart, so the one-hour difference reflects whether summer time is in effect.
How do I convert 9:00 BST to GMT?
9:00 BST equals 8:00 GMT. The same pattern applies to the other common examples: 12:00 BST = 11:00 GMT, 15:00 BST = 14:00 GMT, and 18:00 BST = 17:00 GMT.
Which countries use British Summer Time?
British Summer Time is used in Guernsey, Isle of Man, Jersey, and the United Kingdom. It is the relevant summer reference for organizations scheduling meetings, transport, and customer communications across those jurisdictions.
Which countries use Greenwich Mean Time?
Greenwich Mean Time is used in Burkina Faso, Gambia, Ghana, Guernsey, Guinea, Guinea-Bissau, Iceland, Ireland, Isle of Man, Ivory Coast, Jersey, Liberia, Mali, Mauritania, Saint Helena, Sao Tome and Principe, Senegal, Sierra Leone, Togo, and the United Kingdom. Because GMT covers countries in Europe, the Atlantic, and West Africa, it is a common baseline for international coordination and timestamping.
When should I use BST instead of GMT?
Use British Summer Time when the schedule is specifically tied to the United Kingdom, Guernsey, Jersey, or the Isle of Man during the summer-time period. Use Greenwich Mean Time when the schedule is stated in standard time or when you need a UTC+0 reference shared across GMT-using countries such as Ghana, Iceland, Ireland, and Senegal.