How to calculate a time duration
Enter start and end times in 24-hour format. Enable overnight duration only when the end belongs to the following day.
Crossing midnight
Without the overnight option, an end time earlier than the start is treated as an error. This prevents an accidental 22-hour result when the user intended a two-hour same-day interval.
Privacy and limits
No times are transmitted or stored. The tool calculates durations of zero to 24 hours and does not include calendar dates or time zones.