Time duration calculator between dates and times

Find exact elapsed hours, minutes and seconds between two local date-times, including daylight-saving changes in the selected time zone.

Time zone · find a city

Time zone

Start date (CE)29 Oct 2026

Start timeHH:MM · 24-hour

If the local time occurs twice

End date (CE)29 Oct 2026

End timeHH:MM · 24-hour

If the end time occurs twice

Uses bundled IANA time zone rules 2026f. Governments may change future rules.

Preparing your tool…

How it works

Resolve each local date-time to an instant, then subtract start from end. A calendar day across a daylight-saving change may contain 23 or 25 elapsed hours.

Example

New York midnight on 8 March 2026 to midnight on 9 March spans 23 hours because the clock moves forward.

Is this the same as counting calendar days?

No. Calendar dates and elapsed hours answer different questions. Use the days-between-dates tool for endpoint counting, or this tool for actual time elapsed in one selected zone.