Calculators
Duration Calculator
Exact elapsed time between two dates and times, in the same or different time zones, in days, hours, minutes and seconds.
How it works
Give each moment a date, a time and a time zone. Time resolves both to exact instants (asking you to choose if a local time is nonexistent or ambiguous) and reports the real elapsed time between them.
The breakdown uses 24-hour days of real time, plus totals in hours (to two decimals), minutes and seconds. For a calendar-style difference between dates, use Date Difference.
Worked example
From 9:00 AM on 7 October 2026 in Chennai to 9:37 AM on 9 October 2026 in London: 2 days, 5 hours, 7 minutes — 53.12 hours, 3,187 minutes or 191,220 seconds.
Noon to noon in New York across 8 March 2026 is only 23 hours: clocks skipped an hour that night.
Edge cases handled
- Moments in different time zones.
- Spans that cross a DST change (23- or 25-hour calendar days).
- Nonexistent and ambiguous local times — you choose; nothing is guessed.
- “To” before “From” — shown as a positive duration with a note.