Time duration calculator
Enter two times and get the gap between them three ways: as a decimal, as hours and minutes, and as total minutes. A second time earlier than the first is read as the next day.
How to calculate a duration
Crossing midnight is the case worth being careful about. Subtracting clock times directly gives a negative number when the end is on the next day, which is why so many spreadsheets show a stream of hashes for a night shift. Adding twenty-four hours to a negative result is the fix, and it is what happens here automatically. The remaining ambiguity is genuinely unresolvable: 09:00 to 09:00 could be zero or twenty-four hours. This reads it as twenty-four, on the grounds that nobody asks how long it is between a time and itself.
Questions
Yes. An end time earlier than the start is treated as the following day, so 22:00 to 06:00 gives eight hours.
It reads as twenty-four hours. Asking for the gap between a time and itself is almost always a full day.
Yes, in either format. 5:30 pm and 17:30 are the same input.
For any arithmetic — pay, billing, averages. H:mm cannot be multiplied.
No, both ends are times of day. Use the date calculator for a span across several days.