This time zone calculator helps compare local times across cities or offsets using the fields on the page. Use it to plan calls and avoid off by one hour mistakes around daylight changes.
For raw hour arithmetic without zones, use the time calculator. For elapsed calendar spans, open the date difference calculator. For the time difference between two times on the same clock, use the hours calculator, or the time duration calculator for hours and minutes.
When U.S. and European offsets change
- United States: daylight saving time starts at 2:00 a.m. local time on the second Sunday in March and ends at 2:00 a.m. on the first Sunday in November (15 U.S.C. 260a). For 2026 it ends on November 1. For 2027 it starts on March 14.
- European Union: summer time starts and ends at 01:00 UTC on the last Sunday of March and the last Sunday of October (Directive 2000/84/EC). Every EU country switches at the same moment. In 2026 the dates were March 29 and October 25.
- Exceptions: Hawaii and most of Arizona do not observe DST, according to the U.S. Department of Transportation. The Navajo Nation in Arizona does.
The mismatch weeks every spring and autumn
The U.S. and Europe switch on different Sundays, so the gap between them changes for a few weeks each year. Between the last Sunday in October and the first Sunday in November, the gap is one hour smaller than usual. In spring, between the second Sunday of March and the last Sunday of March, it is also one hour smaller. Recurring meetings set in one zone will look an hour off to people in the other during those weeks.
Time zone calculator example: Los Angeles to London and New Delhi on October 28, 2026
A meeting is set for 9:00 a.m. in Los Angeles on Wednesday, October 28, 2026.
- Los Angeles is still on PDT, UTC−7. U.S. DST does not end until November 1.
- The UK left summer time on October 25, so London is on GMT, UTC+0.
- Convert to UTC: 9:00 + 7 h = 16:00 UTC.
- London: 16:00 + 0 = 4:00 p.m. (The usual gap is 8 hours. This week it is 7.)
- New Delhi, UTC+5:30, no DST: 16:00 + 5:30 = 9:30 p.m.
A week later, on November 4, Los Angeles is on PST (UTC−8). The same 9:00 a.m. meeting is 5:00 p.m. in London and 10:30 p.m. in New Delhi.
Offsets that are not whole hours
Enter these as decimals or as hours and minutes, not rounded:
- India: UTC+5:30, all year
- Nepal: UTC+5:45, all year
If you enter +5 for India, the result will be 30 minutes off.
Southern Hemisphere clocks move the other way
Countries south of the equator that use daylight saving move their clocks forward around September–October and back around March–April. So while the U.S. and Europe fall back, places such as Sydney spring forward. Their gap with Europe can change by two hours over a few weeks. Check each country’s rule against the IANA time zone database, which phones and operating systems use, before entering offsets in the time zone calculator.
Checklist for cross-zone scheduling
- Look up each location’s offset for the meeting date, not today’s date. Confirm the weekday of that date with the day of the week calculator.
- Check the calendar day. A late-afternoon U.S. call can fall on the next day in Asia.
- Send invites in UTC, or include both local times, during the March and October–November mismatch weeks.
Last reviewed: October 2026
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Tips
Confirm whether a city is on daylight saving time for your date. Labels can differ from political borders, and governments sometimes change their rules with little notice. For official background on U.S. clock changes, see the NIST daylight saving time page.