London operates on Greenwich Mean Time (GMT) in winter and British Summer Time (BST) in summer. GMT is defined as UTC+0 and was established at the Royal Observatory in Greenwich, London in 1884 — making London the original reference point for all world time.
The UK moves to BST (UTC+1) on the last Sunday in March and returns to GMT on the last Sunday in October. This single annual change affects the time difference between London and every other city in the world — particularly important for business travellers and remote workers.
London is home to the London Stock Exchange, Lloyd's of London, and the headquarters of major global banks. The city's timezone means it uniquely overlaps with both US morning sessions and Asian closing sessions, making GMT one of the most important business timezones on Earth.
Popular searches include London time vs New York, London time vs Dubai, and what time is it in London right now — reflecting the city's role as a global hub for finance, travel and diaspora communities worldwide.
How London time relates to other major cities right now.
Common questions about time in London, answered in full.
Check the current time in other major cities worldwide.