Time Duration Calculator
Find the exact time between two dates — for shifts, journeys, deadlines and age-style gaps.
Duration
Also equals
How to use it
- Pick the start date and time.
- Pick the end date and time.
- Read the exact duration — days, hours, minutes and seconds.
How it works
Both times are converted to milliseconds since 1 January 1970, subtracted, and the difference is broken into days (÷ 86,400 seconds), hours, minutes and seconds. If you enter the end before the start, the tool swaps them and tells you.
Handy in daily life
Night-shift workers use this to count duty hours across midnight; travellers use it for layovers; freelancers use it to bill hours honestly. It also settles friendly arguments about "how long ago" something happened.
Frequently asked questions
How do I calculate hours between two times?
Enter both date-times above — the tool shows the exact gap in days, hours, minutes and seconds.
Does it work across midnight?
Yes. A shift from 10 PM to 6 AM correctly shows 8 hours.
What if I enter the end time first?
The tool swaps the order automatically and notes it, so you still get the right duration.
Can I include seconds?
Yes — pick times with seconds in your browser's picker and they are counted.