Daylight Saving Time Dates Calculator (When Do the Clocks Change?)
The dates when daylight saving (summer) time starts and ends in a given year in the United States and Canada, or in the European Union and the United Kingdom.
Results
What this tool does
The two big systems follow rules, not fixed dates. In the United States and Canada, summer time starts on the second Sunday of March and ends on the first Sunday of November (at 2:00 local time). In the European Union and the United Kingdom, it starts on the last Sunday of March and ends on the last Sunday of October, with the change at 01:00 UTC in all zones at once. So the dates move from year to year, and the periods do not match: for a few weeks each spring and autumn, the time difference between the US and Europe is an hour different from usual. These rules can be changed by law, and many countries do not use summer time.
Formula
US/Canada: 2nd Sunday of March → 1st Sunday of November · EU/UK: last Sunday of March → last Sunday of October
Variables
| Symbol | Meaning | Unit |
|---|---|---|
yr | Year | — |
rg | Region | — |
SD | Summer time starts — day of the month (always a Sunday) | — |
SM | Summer time starts — month (1–12) | — |
ED | Summer time ends — day of the month (always a Sunday) | — |
EM | Summer time ends — month (1–12) | — |
LN | Days between the two clock changes | d |
Worked example
- Year2026
- Region1
- Summer time starts — day of the month (always a Sunday)8
- Summer time starts — month (1–12)3
- Summer time ends — day of the month (always a Sunday)1
- Summer time ends — month (1–12)11
- Days between the two clock changes238 d
Limitations
- Dates are handled as calendar dates. Time zones, daylight saving changes and public holidays are not taken into account.
- Only Saturdays and Sundays are excluded. Public holidays differ by country and are not deducted.