When the clocks change in 2026, 2027 and 2028
Under the rules in tzdata 2026f, 101 of the 312 zones still move their clocks during the year. 46 follow the North American pattern, forward on the second Sunday in March and back on the first Sunday in November; 36 follow the European pattern of the last Sundays in March and October. The other 11 use a dozen different patterns.
The patterns and their dates
The table groups the zones by the days on which their clocks change and gives the dates for 2026, 2027 and 2028 in the first zone of each group. Dates are local; the clock time of the change differs between zones in the same group. In the European group, 35 of the 36 zones change at the same instant, 01:00 UTC, which falls at 00:00, 01:00, 02:00 and 03:00 on their local clocks.
| Pattern | Zones | 2026 (forward / back) | 2027 | 2028 |
|---|---|---|---|---|
| Forward second Sunday in March, back first Sunday in November | 46 | March 8 / November 1 | March 14 / November 7 | March 12 / November 5 |
| Forward last Sunday in March, back last Sunday in October | 36 | March 29 / October 25 | March 28 / October 31 | March 26 / October 29 |
| Forward first Sunday in October, back first Sunday in April | 8 | October 4 / April 5 | October 3 / April 4 | October 1 / April 2 |
| Forward fourth Saturday in March, back last Saturday in October | 2 | March 28 / October 24 | March 27 / October 30 | March 25 / October 28 |
| Forward last Saturday in March, back last Sunday in October | 2 | March 28 / October 25 | March 27 / October 31 | March 25 / October 29 |
| Forward last Sunday in September, back first Sunday in April | 2 | September 27 / April 5 | September 26 / April 4 | September 24 / April 2 |
| Forward first Saturday in September, back first Saturday in April | 1 | September 5 / April 4 | September 4 / April 3 | September 2 / April 1 |
| Forward first Sunday in September, back first Sunday in April | 1 | September 6 / April 5 | September 5 / April 4 | September 3 / April 2 |
| Forward last Friday in April, back last Friday in October | 1 | April 24 / October 30 | April 30 / October 29 | April 28 / October 27 |
| Forward last Friday in March, back last Sunday in October | 1 | March 27 / October 25 | March 26 / October 31 | March 24 / October 29 |
North America and Europe
The North American pattern has been used by the United States since 2007. In the database it is also followed by zones in Bermuda, Canada, Greenland, Haiti, Mexico, Saint Pierre and Miquelon and Turks and Caicos Islands. Under it, summer time lasts 238 days in 2027; the European pattern gives 217. In 2026 the two groups were out of step for 21 days in March and 7 days around the end of October, so on those days the gap between New York and London was four hours instead of five; the converter shows one of them.
The southern hemisphere
12 zones move their clocks forward in the southern spring, so their summer time runs across the new year. Most of south-east Australia (8 zones) goes forward on the first Sunday in October and back on the first Sunday in April. Auckland and the Chatham Islands start earlier, on the last Sunday in September. Chile goes forward on the first Sunday in September, and Easter Island, two hours behind mainland Chile, changes on the Saturday evening before, which is the same moment.
Fridays, Saturdays and other exceptions
A few zones change on days other than Sunday. Egypt changes on the last Friday in April and back at the end of the last Thursday in October, which the record shows as midnight going into Friday. Israel goes forward on a Friday late in March and back on the last Sunday in October. The two zones of Palestine use Saturdays.
Cuba is the special case of 2026. Release 2026f records that Cuba moved its clocks forward on March 8, 2026 but will not move them back in the autumn; the next change in its record is November 7, 2027. Under the current rules it is therefore on summer time for 310 days of 2027, the longest of any zone. The shortest summer under the current rules is in Egypt, at 182 days.
The clock time of the change
Most zones move their clocks in the small hours of the night. Among the 101 zones that still change, the most common local time for the spring change is 02:00 (74 zones), followed by 03:00 (11). A few move at midnight, which places the change on the night between two days; the record lists it under the later day. For the autumn change the most common clock time is 02:00, used by 56 zones. Times on this site are always the local clock time just before the change.
How long summer lasts
Under the current rules, summer time in 2027 ranges from 182 days to 310 days. The North American pattern gives 238 days, the European pattern 217, and the south-east Australian pattern 183. The difference between the first two comes almost entirely from spring: North America moves forward two or three weeks earlier, while the autumn changes are a week apart. In the southern hemisphere the count runs across the new year, so the 2027 figure for those zones adds the end of the 2026–27 season to the start of the 2027–28 season.
How these dates are produced
The database does not list future dates one by one. It stores rules, such as “last Sunday in March at 01:00 UTC”, and every date on this page comes from applying the rules in release 2026f to 2026, 2027 and 2028. When a government changes its rules, as several did in 2026, a new release changes the dates. Each zone page lists its own dates, and the clock change dates list gives every zone grouped by pattern.
Source: IANA Time Zone Database, release 2026f (public domain), computed by this site; see about the data for definitions. Look up any zone in the converter.