Time zones are legal and political choices as much as astronomical ones. Each country decides its own offset from Coordinated Universal Time (UTC), and many do not stick to whole hours, so the real count is messier than the tidy 24.
The count
- 24 one-hour zones would be the neat version, one for each 15° of longitude.
- In practice there are about 38, because some places use offsets of 30 or 45 minutes: India (UTC+5:30), Sri Lanka (+5:30), Iran (+3:30), Afghanistan (+4:30), Myanmar (+6:30), Nepal (+5:45), the Chatham Islands of New Zealand (+12:45), and parts of Australia (+9:30, +8:45).
- Counting daylight-saving variants — which shift a zone by an hour for part of the year — pushes the effective number higher still.
- The extremes run from UTC−12 (uninhabited US islands) to UTC+14 (the Line Islands of Kiribati), a spread of 26 hours, so at any moment there are two calendar days on Earth at once, sometimes three.
Most and fewest
- France has the most time zones of any country — 12 — once its overseas departments and territories from French Polynesia to the Caribbean are counted.
- Russia has 11, all within one connected landmass — the most of any single country's mainland. The United States also has 11 including territories (6 in the states).
- China spans five geographic time zones but uses a single official time, UTC+8 ("Beijing time"), for the whole country. In far western Xinjiang, this means the sun is directly overhead at around 3 p.m. by the clock, and many locals informally keep an unofficial "Xinjiang time" two hours behind.
- India, despite being wide enough for two zones, also uses a single time (UTC+5:30) nationwide.
- Nepal is the only country on a 45-minute offset by choice, set so its meridian passes over a landmark near Kathmandu.
The International Date Line
The date line runs roughly down the 180th meridian in the Pacific, but it zigzags around island nations so that each country keeps a single date. Kiribati moved the line far to the east in 1995, so that its scattered islands — which had straddled the line — would all share the same day; as a result, its Line Islands are at UTC+14 and are the first inhabited place on Earth to enter each new day and each new year. Samoa jumped the line in 2011, skipping 30 December entirely, to be on the same business day as Australia and New Zealand instead of the United States.
Each country page lists its region and neighbours — useful context for time-zone and date-line questions.
Country fact pages →