What Is UTC?
UTC, or Coordinated Universal Time, is the shared reference time used to compare local times around the world.
At a glance
| Full name | Coordinated Universal Time. |
|---|---|
| Offset | UTC is the zero point: UTC+0. |
| Useful with | time zone converter, time zone groups, and IANA time zones. |
UTC in plain English
UTC is the time standard that lets different places describe their local time in one shared language.
UTC is the baseline
When a place is UTC+2, its local clock is two hours ahead of UTC. When a place is UTC-7, its local clock is seven hours behind UTC.
- UTC+0 is the reference point.
- UTC offsets can include half-hour or 45-minute differences.
- Many computers, servers, and logs store time in UTC.
Local time is UTC plus an offset
To understand a city page, look at the local time and the offset together. Then use the time zone converter if you need to turn that time into a meeting, call, or reminder.
UTC, GMT, and time zones
People often use GMT and UTC casually, but they are not the same idea in every context.
UTC is the modern standard
UTC is the technical reference used by time-zone databases. GMT is a historic time reference and also a label used on some public clock pages.
- Use UTC for technical accuracy.
- Use city or IANA pages for real local time.
- Use GMT pages when that is the abbreviation people search for.
DST can change the offset
A city may be UTC-5 in winter and UTC-4 in summer. That is why daylight saving time matters when you plan across dates.
Related tools and guides
Frequently asked questions
Is UTC a time zone?
UTC is a time standard and reference point. It is often used like a time zone because it has a fixed UTC+0 offset.
What does UTC+3 mean?
UTC+3 means the local clock is three hours ahead of Coordinated Universal Time.
Does UTC change for daylight saving time?
No. UTC stays fixed. Local time zones may move closer to or farther from UTC during daylight saving time.