Explainers
Longer reads built on the same clock records as the rest of the site. Each answers one question with tables and charts computed from tzdata 2026f.
- Which places have stopped changing their clocks144 time zones used daylight saving time after 1970 and stopped. When the big exits happened, and how each zone left, from tzdata 2026f.
- Half-hour and 45-minute time zonesThe 14 time zones on half-hour or 45-minute offsets, since when, and the 12 that gave one up after 1970, from tzdata 2026f.
- How often time zones change459 changes of standard time from 1970 to 2026: the busiest years, the zones and countries that changed most, and the 148 that never did.
- When the clocks change in 2026, 2027 and 2028Daylight saving dates for 2026 to 2028 in all 101 zones that still change clocks, grouped by pattern, from tzdata 2026f.
- When local mean time ended298 zones start with local mean time in the tz database. When each place switched to a standard offset, from 1847 to 1952.
- How far clocks run from the sunIn 233 of 312 time zones the clock runs ahead of mean solar time. The largest gaps, how summer time widens them, from tzdata 2026f.
- How to read a tz database zone nameWhat Europe/Paris and America/Argentina/Buenos_Aires mean: the 312 zone names, 237 alternative names, shared records and abbreviations.