Time Duration Calculator
Find the duration between two times of day.
Assumptions used in this calculation
- Overnight ranges: If the end time is earlier than the start time, the calculator assumes it falls on the next day.
About this calculator
Subtracting one clock time from another seems simple until the times cross midnight or aren't on a clean hour, and doing base-60 subtraction in your head (like 17:30 minus 9:00, or 23:15 minus 22:45) is a common source of small arithmetic mistakes. This calculator takes a start time and an end time and returns the exact duration in hours and minutes, automatically detecting an overnight range (where the end time is earlier than the start time) and rolling it over to the next day instead of returning a negative or nonsensical result. It's useful for timing a meeting, a workout, a movie, a night shift that runs past midnight, or any activity where you know the start and end clock times but need the elapsed duration.
Worked example
9:00 AM to 5:30 PM
Result: 8h 30m
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