GMT time
What GMT is
Greenwich Mean Time (GMT) is UTC+0, the reference time at the Greenwich meridian. GMT itself never changes. The UK uses GMT only in winter: from the last Sunday in March to the last Sunday in October it is on BST (UTC+1), so "GMT" and "UK time" are an hour apart in summer.
Offsets of major time zones
| Time zone | January | July |
|---|---|---|
| Eastern Time (New York) | UTC−5 EST | UTC−4 EDT |
| Central Time (Chicago) | UTC−6 CST | UTC−5 CDT |
| Pacific Time (Los Angeles) | UTC−8 PST | UTC−7 PDT |
| UK time (London) | UTC+0 GMT | UTC+1 BST |
| Central European Time (Paris) | UTC+1 CET | UTC+2 CEST |
| India Standard Time (India) | UTC+5:30 IST | UTC+5:30 IST |
| Singapore Time (Singapore) | UTC+8 SGT | UTC+8 SGT |
| Japan Standard Time (Tokyo) | UTC+9 JST | UTC+9 JST |
| Australian Eastern Time (Sydney) | UTC+11 AEDT | UTC+10 AEST |
Southern-hemisphere places such as Sydney use daylight saving in January, not July.
Handy for
- Times quoted in GMT for broadcasts, sport and flights
- Converting "GMT+2" style offsets to real times
- Checking the UK's winter time
- Matching logs written in GMT or UTC
Questions
Is the UK always on GMT?
No. The UK uses GMT in winter and BST (British Summer Time, GMT+1) from the last Sunday in March to the last Sunday in October.
Is GMT the same as UTC?
For everyday purposes, yes: both are UTC+0 and neither changes. UTC is the precise standard used by computers and aviation.
Does GMT change for daylight saving?
No. GMT is always UTC+0. Places change from GMT to their summer time instead.
More time zone pages
Or open the full Time Zones meeting planner and world clock.