Turn a United Kingdom Time reading into Coordinated Universal Time. The panels show both clocks live, and the roller lets you line up any GMT/BST time against its UTC equivalent.
United Kingdom Time
Coordinated Universal Time
US Eastern Time
THE CLOCKS ABOVE ALWAYS SHOW THE LIVE CURRENT TIME. THE ROLLER BELOW IS A LOOKUP TOOL — ROTATING IT NEVER CHANGES THEM.
GMT/BST is 1 hour ahead of UTC
ET is 5 hours behind UTC
United Kingdom is 6 hours ahead of United States (Eastern)
| GMT/BST | UTC | Date |
|---|---|---|
| 01:00 | 00:00 | Same day |
| 02:00 | 01:00 | Same day |
| 03:00 | 02:00 | Same day |
| 04:00 | 03:00 | Same day |
| 05:00 | 04:00 | Same day |
| 06:00 | 05:00 | Same day |
| 07:00 | 06:00 | Same day |
| 08:00 | 07:00 | Same day |
| 09:00 | 08:00 | Same day |
| 10:00 | 09:00 | Same day |
| 11:00 | 10:00 | Same day |
| 12:00 | 11:00 | Same day |
| 13:00 | 12:00 | Same day |
| 14:00 | 13:00 | Same day |
| 15:00 | 14:00 | Same day |
| 16:00 | 15:00 | Same day |
| 17:00 | 16:00 | Same day |
| 18:00 | 17:00 | Same day |
| 19:00 | 18:00 | Same day |
| 20:00 | 19:00 | Same day |
| 21:00 | 20:00 | Same day |
| 22:00 | 21:00 | Same day |
| 23:00 | 22:00 | Same day |
| 00:00 | 23:00 | Previous day in UTC |
United Kingdom Time is the local clock in the United Kingdom. Converting it to UTC removes the local offset so the time can be shared with anyone in the world without ambiguity — which is exactly why UTC is used for servers, aviation and international scheduling.
Greenwich Mean Time is measured at the Royal Observatory in Greenwich and is the historical basis for the modern UTC standard.
Subtract the current offset shown in the offset panel from the local GMT/BST time. If the result goes below 00:00, UTC is still on the previous date. Use the roller to read the pairing directly instead of doing the arithmetic.
Because GMT/BST observes daylight saving time, the gap to UTC is not fixed — every clock and table on this page is calculated live from the Europe/London IANA database, so today's real offset is always what you see.
Early-morning or late-night local times frequently sit on a different UTC date. The converter labels every selection as SAME DAY, NEXT DAY or PREVIOUS DAY so a deadline written in UTC is never off by 24 hours.
The UK switches between GMT (UTC +00:00) in winter and British Summer Time (UTC +01:00) from late March to late October, so UTC and London time are only identical for part of the year.