Time Calculator
Add or subtract a duration to a time, or find exactly how much time passes between two times of day.
If the end time is earlier than the start time, it's treated as happening the next day.
Frequently Asked Questions
What happens if I subtract more time than the start time has?
It wraps around to the previous day — for example, subtracting 2 hours from 01:00 gives 23:00, with a day offset shown.
Can I calculate duration across midnight?
Yes — in “Duration between two times,” if the end time is earlier than the start time, it's treated as happening the next day (e.g. 22:00 to 02:00 gives a 4-hour duration).