Time Duration Calculator
Duration between two times (same day)
| Start time | |
| End time |
Result appears here.
Duration between two dates and times
| Start | |
| End |
Result appears here.
How it works
Duration is calculated by subtracting the start from the end. For the time-only calculator, if the end time is earlier than the start time it is treated as crossing midnight (next day). For the date-and-time calculator, the exact difference in days, hours, minutes, and seconds is shown (if the end is before the start, the difference is shown as negative in total and the magnitude is explained).
Times are interpreted in your local time. Daylight saving time changes can make some local clock differences differ from simple hour counts.
How it works
Time duration is the elapsed time between a start and end. This can be calculated for times within a day or between full date-and-time values.
How it’s calculated
- Convert times to a common unit (like minutes or seconds), subtract start from end, and handle day rollover (overnight) or date differences when provided.
- Result can be shown as hours/minutes/seconds and/or total units.
Worked example
From 22:00 to 02:00 the next day is 4 hours (overnight).
For general information only. Time zone and daylight saving differences are not automatically inferred unless you enter them explicitly.
How to use the Time Duration Calculator
It takes a few seconds, and every figure is calculated in your browser.
- Enter the start time.
- Enter the end time.
- Enter the start date and time.
- Enter the end date and time.
- Press Calculate — the result appears in the dark panel beside the form.
- Use Copy, CSV, Share or Print under the result if you want to keep it.
Time Duration Calculator — frequently asked questions
What formula does the Time Duration Calculator use?
Convert times to a common unit (like minutes or seconds), subtract start from end, and handle day rollover (overnight) or date differences when provided. Result can be shown as hours/minutes/seconds and/or total units.
How does the Time Duration Calculator work?
Duration is calculated by subtracting the start from the end. For the time-only calculator, if the end time is earlier than the start time it is treated as crossing midnight (next day). For the date-and-time calculator, the exact difference in days, hours, minutes, and seconds is shown (if the end is before the start, the difference is shown as negative in total and the magnitude is explained). Times are interpreted in your local time.
Can you walk through a worked example?
From 22:00 to 02:00 the next day is 4 hours (overnight).
Last updated 10 November 2026 · Formula, worked example and assumptions are documented above, and every result is calculated in your browser.