DST Dates Are Not Universal
One of the most confusing aspects of daylight saving time is that countries do not change their clocks on the same date. The Northern and Southern Hemispheres transition at opposite times of year, and even within the Northern Hemisphere, North America and Europe change clocks on different dates — creating a two-to-three week period each spring and autumn when the offset between regions changes.
United States and Canada
- Start: Second Sunday of March at 2:00 AM (clocks spring forward to 3:00 AM)
- End: First Sunday of November at 2:00 AM (clocks fall back to 1:00 AM)
- Exceptions: Arizona (except Navajo Nation), Hawaii, U.S. territories (Puerto Rico, Guam, etc.) do not observe DST. Parts of Saskatchewan, Canada, also stay on standard time.
European Union and UK
- Start: Last Sunday of March at 1:00 AM UTC (2:00 AM local in most zones)
- End: Last Sunday of October at 1:00 AM UTC
- All EU member states, plus the UK, Norway, Switzerland, and several other European countries, change on the same dates.
The Transatlantic Gap
Because the U.S. and Europe change clocks on different Sundays, there are periods when the time difference between the two regions is temporarily different from normal. For example, when the U.S. changes clocks in mid-March but Europe doesn't change until late March, New York is one hour closer to London than usual for about two weeks.
Australia and New Zealand
Because Australia is in the Southern Hemisphere, its seasons are reversed:
- Start (spring in Southern Hemisphere): First Sunday of October
- End (autumn in Southern Hemisphere): First Sunday of April
- Not all states observe DST — Queensland, Western Australia, and the Northern Territory do not.
- New Zealand starts DST on the last Sunday of September and ends on the first Sunday of April.
Middle East and Other Regions
Countries that observe DST in the Middle East and North Africa (Iran, Israel, Jordan, Lebanon, Morocco, Palestine) each have their own transition dates, which can vary by year and are sometimes adjusted for religious observances such as Ramadan.
Practical Tips
- Always verify current DST dates from an authoritative source like the IANA timezone database or timeanddate.com before scheduling international events.
- During the transition weeks when only some regions have changed, double-check all international meeting times.
- Phone and computer clocks update automatically in most cases, but older devices, appliances, and car clocks may need manual adjustment.