The numeric ladder · UTC−11:00 to UTC+14:00
Every UTC offset
in use right now.
The world currently runs on 37 offsets, from UTC−11:00 to UTC+14:00 — including 11 that aren't whole hours. An offset is a number, not a time zone: each rung below hosts every named zone that keeps it. Browsing zones instead? See the zones index.
Offsets in use
37
UTC−11:00 west to UTC+14:00 east
Total span
25h
the same instant, 25 hours of clock faces
Not whole hours
11
half- and quarter-hour offsets
Zones that shift
125
IANA zones that hop rungs with DST
The ladder · west to east
37 rungs around the planet.
each card shows that offset's local sky, right now
How offsets work
A number,
not a place.
Every clock on Earth is set relative to one reference: Coordinated Universal Time (UTC), kept by a network of atomic clocks. A UTC offset is simply the difference between a region's clocks and that reference — UTC+07:00 means seven hours ahead, UTC−10:00 means ten hours behind. Add the offset to UTC and you have the local time, no further rules required.
An offset is not a time zone — this is the distinction people most often get wrong. A single offset can host dozens of named zones with entirely different daylight-saving rules: UTC+02:00 is currently kept by Paris (which will leave it in October), Cairo (which leaves it in April), and Johannesburg (which never leaves). Two places sharing an offset today may be an hour apart next month. That's why software stores zone identifiers, while offsets are best for arithmetic and quick reading of a timestamp.
The ladder runs from UTC−11:00 to UTC+14:00 — a 25-hour span, not 24, because nations near the Date Line chose which side of it to live on. Kiribati moved its eastern islands to UTC+14 in 1995 so the whole country could share a business week. And the half- and quarter-hour rungs are politics and geography, not astronomy: India compromised between two hour-lines at +05:30, Nepal nudged 15 minutes further to keep its own clock, and the Chatham Islands hold +12:45 for the same reason.
Curiosities
Four oddities of the ladder.
Same time, different day
UTC+14 and UTC−10 show identical clock faces.
When it’s 14:00 Tuesday in Honolulu (UTC−10), it’s 14:00 Wednesday in Kiritimati (UTC+14) — the same time, 24 hours apart. The two rungs bracket the entire ladder.
The 45-minute club
Nepal runs at UTC+05:45 — one of only three.
Just three offsets aren’t divisible by 30 minutes: Nepal (+05:45), the Chatham Islands (+12:45), and Eucla, Australia (+08:45) — a roadhouse community of about 50 people with its own offset.
One country, twelve rungs
France spans 12 offsets thanks to its territories.
From French Polynesia at UTC−10 to Wallis & Futuna at UTC+12, the French Republic touches more rungs of the ladder than any other country — Russia and the United States each manage 11.
The ladder moves
When DST flips, whole regions hop a rung.
Each March and October, hundreds of millions of clocks step one rung up or down overnight. The ladder itself is stable — it’s the zones that climb between rungs.
Frequently asked questions
Common questions about UTC offsets and how they relate to time zones. Can't find what you need? Email [email protected].
- What’s the difference between UTC and GMT?
- UTC is the modern atomic-clock standard; GMT is the historical astronomical time at the Greenwich meridian. They differ by less than a second and are interchangeable in everyday use — but UTC is the correct term, and "GMT−10" and "UTC−10" mean the same offset.
- Why do some places use half-hour offsets?
- Geography and politics, not astronomy. Countries sitting midway between two hour-lines sometimes split the difference: India chose UTC+05:30, Iran +03:30, Newfoundland −03:30. Nepal and the Chatham Islands went further, to 45-minute marks, to keep clocks distinct from larger neighbours.
- What are the highest and lowest UTC offsets?
- The highest is UTC+14:00, used by Kiribati’s Line Islands (Kiritimati). The lowest in use is UTC−11:00, kept by American Samoa and Niue. UTC−12:00 exists in the database for two uninhabited US islands, but no one lives there to keep it.
- Is UTC itself a time zone?
- No — UTC is the reference standard the offsets count from. No country keeps "UTC" as its civil time, though several zones (Iceland, Ghana, Senegal) sit at UTC+00:00 year-round, and aviation, shipping, and server logs run on UTC by convention.
Free · Developer API
Filter zones by offset.
One query returns every zone whose standard time is a given offset, each with its live offset and DST status.
Also in the API: time zones by coordinates, conversions that flag daylight saving gaps, and abbreviations decoded.
Moving off WorldTimeAPI? Our drop-in replacement needs no key.