Measure the stretch between two date-and-time values, broken into days, hours, minutes and seconds and totalled in seconds. It's handy for timesheets, events and experiments, and it all happens in your browser.
Time Duration Calculator works out the answer precisely from local calendar dates, so there are no timezone or daylight-saving surprises.
Yes — set the time with seconds and the result includes them.
Yes — the duration is the absolute difference either way.
No — it runs in your browser.
Pick a start and end time