Duration Calculator
Calculate the exact time between two dates in days, hours, minutes, and seconds.
Select a start and end date to see the duration.
About This Tool
The Time Duration Calculator computes the exact difference between two datetime values and expresses it in multiple units simultaneously — days, hours, minutes, seconds, total days, total hours, total minutes, total seconds, and total weeks.
A negative result means the end date is before the start date. Leap years, different month lengths, and DST transitions are all handled correctly using millisecond arithmetic.
How to Use
- Enter a start date and time, or click Now to use the current time.
- Enter an end date and time.
- All duration metrics update instantly.
Use Cases
Project managers calculate task durations. Event organizers measure time until a deadline. Developers compute time elapsed between log events. Athletes track training session durations.
FAQ
- Does it account for leap years? — Yes. The calculation uses actual millisecond arithmetic, so leap years, different month lengths, and DST transitions are all handled correctly.
- What if end is before start? — The result is displayed with a minus sign showing the backward duration.