Compare BST vs GMT
See the current BST and GMT offset, understand how daylight saving affects the difference, and find the best hours to schedule meetings.
How to Find the Time Difference Between BST and GMT
Open the BST vs GMT converter: Go to https://www.xconvert.com/time-converter/bst-vs-gmt to open the visual comparison grid with BST and GMT already loaded as the two rows. This page is useful when you are scheduling a London-based summer meeting, checking a UK travel itinerary, or confirming whether a timestamp marked “BST” should be read one hour ahead of Greenwich Mean Time.
Add comparison cities if your schedule involves more than the UK: Click “+ Add City” and add places such as London, Dublin, or Reykjavik to compare how British Summer Time aligns with nearby business hubs and aviation routes. This is especially useful for airlines, media teams, and financial staff who work with UK summer hours but may also need to confirm whether Ireland or Iceland is following the same clock on a given date.
Drag across the grid to select the time window you want to compare: Click “Select” if needed, then drag across the BST row from 9:00 AM to 11:00 AM BST; the highlighted purple range will show the corresponding time in GMT as 8:00 AM to 10:00 AM GMT, because BST is exactly 1 hour ahead of GMT. You can drag the center of the selection to move the meeting block later in the day, or use the left and right handles to resize it when testing whether a UK summer work session overlaps with teams that record time in GMT.
Export the selected time range for real scheduling use: Once your range is selected, use the export options for ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link to send the confirmed BST-to-GMT conversion to colleagues or clients. For example, a broadcast team can share an ICS file so everyone sees the event in their own local calendar correctly, while a project manager can copy the link into Slack or email to avoid confusion over whether the meeting is listed in summer UK time or standard GMT.
BST vs GMT Offset Explained
BST (British Summer Time) is UTC+1, while GMT (Greenwich Mean Time) is UTC+0, so BST is exactly 1 hour ahead of GMT. That means when it is 9:00 AM BST, it is 8:00 AM GMT; when it is 6:30 PM BST, it is 5:30 PM GMT. This difference matters most in summer scheduling because many people casually refer to “UK time” as GMT even when the United Kingdom is actually observing BST.
BST is the daylight saving time used in the United Kingdom, including major population and business centers such as London (metro population about 14 million), Birmingham, Manchester, Glasgow, and Bristol during the warmer part of the year. GMT is the standard time at the Prime Meridian (0° longitude) and is used year-round as a reference for global coordination, navigation, server logs, and some international schedules. In practical terms, if a London office says a meeting is at 2:00 PM BST in July, anyone converting it to GMT should join at 1:00 PM GMT.
The seasonal change is what creates the difference. In the UK, BST begins on the last Sunday in March when clocks move forward by one hour at 1:00 AM GMT, and BST ends on the last Sunday in October when clocks move back by one hour at 2:00 AM BST to return to GMT. For 2025, BST starts on 30 March 2025 and ends on 26 October 2025; during that period, BST remains UTC+1 and GMT remains UTC+0.
This distinction is important for industries that run on precise timing. London financial markets, international newsrooms, airline operations, cloud infrastructure teams, and remote software companies often need to know whether a timestamp is in BST or GMT because a one-hour error can affect trading windows, departure coordination, or production releases. For example, a 10:00 AM BST operations handoff from a London team corresponds to 9:00 AM GMT, which can change whether a team using GMT-based logs sees the event as on time or delayed.
A common source of confusion is that many people use “GMT” as shorthand for UK local time all year, but that is not technically correct in summer. From late March to late October, the UK is generally on BST, not GMT, so any calendar invite, webinar, or flight-related communication that says “UK time” should be checked against the actual date. If the event falls in July, August, or September, it is usually BST = GMT+1, not GMT itself.
Frequently Asked Questions
What is the exact time difference between BST and GMT?
BST is 1 hour ahead of GMT. Specifically, BST = UTC+1 and GMT = UTC+0, so if it is 12:00 PM BST, it is 11:00 AM GMT. This offset applies only while British Summer Time is in effect; outside that period, the UK returns to GMT and there is no difference.
Is BST always 1 hour ahead of GMT?
No, BST is only used during the UK daylight saving period, which runs from the last Sunday in March to the last Sunday in October each year. During those months, BST is 1 hour ahead of GMT, but in winter the UK switches back to GMT, so the difference becomes 0 hours. This is why a date is essential when converting between BST and GMT.
When do BST and GMT become the same again?
BST and GMT become the same when the UK ends daylight saving time on the last Sunday in October and moves clocks back by one hour. In 2025, that happens on 26 October 2025, after which UK local time returns to GMT (UTC+0). From that point until the next spring transition, there is no BST-to-GMT difference.
Why do people confuse BST with GMT so often?
The confusion happens because many people say “GMT” when they really mean “UK time,” even though the UK does not use GMT all year. In summer, cities such as London, Manchester, and Edinburgh are on BST (UTC+1), so labeling a summer event as GMT can make attendees join an hour late or early. This is especially common in international business, webinars, and travel bookings where “London time” is assumed rather than checked.
How do I convert a meeting time from BST to GMT?
Subtract 1 hour from the BST time to get GMT during the daylight saving period. For example, 3:00 PM BST = 2:00 PM GMT, and 8:30 AM BST = 7:30 AM GMT. Using the visual grid on the converter page helps confirm whether the date falls within the BST season, which is important because the conversion changes once the UK returns to GMT in late October.
Is London on BST or GMT right now?
London is on BST between the last Sunday in March and the last Sunday in October, and on GMT for the rest of the year. So the correct answer depends on today’s date, not just the city name. If you are scheduling with London in summer, assume BST (UTC+1) unless the date falls after the autumn clock change.
Does BST affect flights, train schedules, or business hours in the UK?
Yes, BST affects all local civil time in the UK during the summer period, including flight departures, rail timetables, office hours, TV schedules, and event start times. A departure listed at 7:00 PM in London in July is normally 7:00 PM BST, which is 6:00 PM GMT. This matters for travelers connecting from GMT-based schedules and for companies coordinating logistics across multiple time standards.
Is GMT the same as UTC when comparing it with BST?
For everyday scheduling, GMT and UTC are usually treated the same, both representing UTC+0, while BST remains UTC+1. There are technical differences in how UTC is maintained as an atomic time standard and GMT as a time zone label, but for meeting planning and calendar conversion, the practical result is that BST is 1 hour ahead of both GMT and UTC during British Summer Time. This is why many global tools show London as UTC+1 in summer and UTC+0 in winter.