How many time zones are there?
There are 37 time zones if you count each standard offset from UTC once. That is 13 more than the 24 you get by cutting the globe into one-hour slices.
Countries choose their own clock time. That is why 11 of the offsets are not whole hours, and why Kiritimati is 14 hours ahead of UTC.
What this page counts
This page counts standard offsets. A standard offset is the time a place keeps when daylight saving time is not in force.
Daylight saving adds 2 more offsets that no place uses as its standard time: UTC-02:30 in St Johns, Canada, and UTC+13:45 in Chatham, New Zealand.
| What you count | Number |
|---|---|
| Standard offsets in use | 37 |
| Offsets in use over a year, counting daylight saving time | 39 |
| Standard offsets that are not whole hours | 11 |
| Time zones in the IANA database | 312 |
The 11 offsets that are not whole hours
Most offsets are whole hours. These are the exceptions, with every time zone that uses them.
The one people remember is UTC+05:45, the time in Nepal. It is 15 minutes ahead of India, which is itself 30 minutes off the hour.
Chatham, New Zealand, keeps its clocks 45 minutes ahead of Auckland.
| Offset | Time zones | Used in |
|---|---|---|
| UTC-09:30 | Marquesas | French Polynesia |
| UTC-03:30 | St Johns | Canada |
| UTC+03:30 | Tehran | Iran |
| UTC+04:30 | Kabul | Afghanistan |
| UTC+05:30 | Kolkata, Colombo | India, Sri Lanka |
| UTC+05:45 | Kathmandu | Nepal |
| UTC+06:30 | Yangon | Myanmar, Cocos (Keeling) Islands |
| UTC+08:45 | Eucla | Australia |
| UTC+09:30 | Adelaide, Darwin, Broken Hill | Australia |
| UTC+10:30 | Lord Howe | Australia |
| UTC+12:45 | Chatham | New Zealand |
Why 312 zones but only 37 offsets
The IANA database records clock history, not just today's offsets.
A place gets its own entry when its clocks have differed from nearby clocks at any time since 1970.
Argentina has 12 entries, and today all 12 keep UTC-03:00 all year. They are separate entries because their clocks have not always matched.
A computer needs that history to show the right local time for an old date. For the everyday question, the number of offsets is the better answer.
Time zones in the United States
Not counting its overseas territories, the United States uses 6 standard offsets. They run from UTC-10:00 in Honolulu to UTC-05:00 in New York.
The database lists 29 zones for the United States. The extra entries are places whose clock history differs from their neighbors.
The page on time zones by state shows which zone each state uses and the time in each one now.
Time zone chart
Every standard offset in use, from west to east. Each row gives example places and how many zones in the database share the offset.
Common questions
Why do people say there are 24 time zones?
A day has 24 hours, so cutting the globe into one-hour slices gives 24 zones. Countries set their own clocks, so the real count of standard offsets is 37.
How many time zones are there counting daylight saving time?
Counting daylight saving time, 39 offsets are in use at some point in a year. Of those, 2 are used only during daylight saving.
Which time zone is furthest ahead?
UTC+14:00, the time in Kiritimati, Kiribati. It is the first place to reach each new day.
Sources
We checked each fact on this page against these sources on 30 September 2026. Times, offsets and clock changes come from the time zone database.