Coordinated Universal Time (UTC) is the global time standard. Every timezone on Earth is defined as an offset from it: New York is UTC-5 (or -4 in summer), London is UTC+0 (or +1), India is UTC+5:30, Tokyo is UTC+9.
UTC is maintained by hundreds of atomic clocks around the world, averaged together. Because atomic time is more stable than the Earth’s slightly irregular rotation, leap seconds are occasionally added to keep UTC within 0.9 seconds of astronomical time.
UTC has no daylight saving and no location. That makes it the universal language of time for aviation, servers, logs, finance, and science. When systems in different countries need to agree on “when,” they use UTC and convert to local time only for display.
“UTC+5:30” means the local clock is 5 hours 30 minutes ahead of UTC. If it’s 12:00 UTC, it’s 5:30 PM in India and 7:00 AM in New York (winter). Try it live with our UTC converter.
Coordinated Universal Time — the compromise abbreviation between the English CUT and French TUC.
No. UTC never changes, which is exactly why it is used as the global reference.
Strictly, UTC is a time standard. Some places (like Iceland) use UTC+0 as their local timezone year-round.