About Greenwich Mean Time
- Standard offset
- UTC±0
- Daylight offset
- UTC+1
- Abbreviations
- GMT, BST
- Observes DST
- Yes
Used in: United Kingdom, Ireland, Portugal.
GMT is the zero point from which the whole grid of world time was originally measured, set by the Royal Observatory at Greenwich.
Daylight saving time
Greenwich Mean Time observes daylight saving time. The next transition is on Sunday, October 25, 2026, when clocks fall back from BST to GMT.
See the daylight saving time page for transition dates across every time zone.
Daylight today
Sun times at the representative location for Greenwich Mean Time.
- Sunrise
- 4:47 AM
- Sunset
- 9:13 PM
- Day length
- 16h 25m
Major cities in Greenwich Mean Time
The current local time in these cities matches Greenwich Mean Time.
Browse all cities to see the current local time anywhere.
Convert Greenwich Mean Time to
Frequently asked questions
- What is Greenwich Mean Time (GMT)?
- Greenwich Mean Time (GMT) is UTC+0, shifting to UTC+1 in summer — the historic reference clock for Britain, Ireland, and Portugal.
- What is GMT in UTC?
- GMT is UTC±0 in standard time and UTC+1 during daylight saving time.
- Does Greenwich Mean Time observe daylight saving time?
- Yes. The next change is on October 25, 2026, when clocks fall back from BST to GMT.