What Time Zone Is the UK In? GMT and BST Explained
The UK uses Greenwich Mean Time (GMT), or UTC+0, in winter and British Summer Time (BST), or UTC+1, in summer. For an international call, you therefore need the date as well as the stated UK time. A meeting at 9:00 am in London has a different UTC equivalent in January and July, even though the clock on the invitation looks the same.
When the UK uses GMT and BST
GMT is the UK's winter time. In 2026, the clocks move forward on 29 March, beginning BST, and move back on 25 October, returning to GMT. The corresponding changes take place on 28 March and 31 October in 2027, then on 26 March and 29 October in 2028. On the spring change, the UK advances from UTC+0 to UTC+1; on the autumn change, it returns to UTC+0.
This seasonal change matters near the clock-change Sundays. If somebody abroad schedules a call for 10:00 am UK time, check whether that means GMT or BST on the chosen date. Writing both the local time and the offset removes doubt: for example, 10:00 am UK time (UTC+1). It is especially useful for a recurring meeting that continues through spring or autumn.
Why Greenwich gives GMT its name
The Greenwich meridian, which passes through Greenwich in south-east London, is the reference line at zero degrees longitude. Longitudes are measured east or west from this prime meridian, and the world's time zones are described by their offsets from the zero reference. That is why Greenwich appears in the name Greenwich Mean Time and why UK winter time sits at the starting offset rather than one hour to either side.
The meridian is a geographical reference, while a time standard is a method of keeping and distributing time. This distinction explains a common technical correction: GMT and UTC are not strictly identical concepts. GMT developed from mean solar time at Greenwich, whereas UTC is the modern international time standard derived from atomic time and adjusted with leap seconds. For ordinary calls, train plans and calendar entries, both represent the same civil clock offset of zero hours.
Time differences with Europe, the US and India
Much of continental Europe, including France, Germany, Spain, Italy and Poland, normally runs one hour ahead of the UK. When it is 8:00 am in London, it is usually 9:00 am in Paris or Berlin. Europe does not all share one zone, however: Portugal uses the same main seasonal offsets as the UK, while countries farther east may be two or more hours ahead. A city name is safer than the broad label “European time”.
The United States spans several time zones, so there is no single UK–US difference. New York is commonly five hours behind London, Chicago six, Denver seven and Los Angeles eight. For example, 3:00 pm in London is commonly 10:00 am in New York and 7:00 am in Los Angeles. The difference can briefly change because the UK and US do not always begin and end daylight saving time on the same dates. Around March and late October or early November, confirm both cities for the actual day.
India uses one national time throughout the year and does not make a seasonal clock change. It is 5 hours 30 minutes ahead of the UK while Britain is on GMT and 4 hours 30 minutes ahead while Britain is on BST. A 9:00 am London call therefore falls at 2:30 pm in India during UK winter, but at 1:30 pm during UK summer. The half-hour offset is easy to miss when someone calculates the difference from memory.
Does every part of the UK share the same time?
England, Scotland, Wales and Northern Ireland all use GMT in winter and BST in summer. The same clock applies on the UK's inhabited islands that form part of those countries, so travelling from London to Belfast, Edinburgh, Cardiff, the Isle of Wight, Anglesey, Orkney or Shetland does not require a time-zone change. The Crown Dependencies are not constitutionally part of the UK, although Jersey, Guernsey and the Isle of Man keep the same clock pattern. British Overseas Territories are separate locations and may use very different zones, so “UK time” should not be assumed for them.
Common questions
Is the UK in GMT or BST right now?
It depends on the date. The UK uses GMT during winter and BST, which is one hour ahead, during summer.
What is the UK's UTC offset?
The UK is UTC+0 while observing GMT and UTC+1 while observing BST. The offset changes when the clocks change in spring and autumn.
Are GMT and UTC exactly the same thing?
No, they have different technical definitions: GMT relates historically to mean solar time, while UTC is an atomic time standard. For everyday civil time, both indicate a zero-hour offset.
Is Northern Ireland in the same time zone as London?
Yes. Northern Ireland follows the same GMT and BST schedule as England, Scotland and Wales, so Belfast and London show the same local time.
How far ahead of New York is the UK?
The UK is commonly five hours ahead of New York. The gap can temporarily become four hours because Britain and the US change their clocks on different dates.
Cookie policy