Time Duration Calculator
How long between two times. Overnight and multi-day spans included.
Times are read on a 24 hour clock. Your entries save in your browser, nothing is uploaded.
Two times, one gap. It sounds trivial until the shift runs past midnight, or the meeting started at 13:20 and ended at 09:05 the next morning, and suddenly you are counting on your fingers and second-guessing the answer.
This page takes the start and the end and gives you the gap. Overnight spans are assumed when the end time is earlier than the start, which is nearly always what you meant. If the span is genuinely longer than a day, switch the dates on and it counts those too.
The result comes in three formats because different people ask for different ones: 8h 30m for a message, 8:30:00 for a spreadsheet, 8.50 for a timesheet.
How the duration is worked out
The duration is the end time minus the start time. When the end is earlier in the day than the start, the span is taken to cross midnight and 24 hours are added. Any break you enter is then subtracted. With dates switched on, the whole days between the two dates are counted as well.
The answer is shown three ways: hours and minutes, clock format for spreadsheets, and decimal hours for payroll.
A worked example
A night shift from 22:30 to 06:15 crosses midnight, so the span is 7 hours 45 minutes. Take off a 30 minute unpaid break and the result is 7 hours 15 minutes, which is 7:15:00 in a spreadsheet and 7.25 hours on a timesheet.
Mistakes to watch for
Mixing up 12 and 24 hour times. 12:30 AM is just after midnight and 12:30 PM is just after noon, and entering the wrong one moves the answer by twelve hours. The military time converter settles any doubt.
Reading decimal hours as hours and minutes. 7.25 hours is 7 hours 15 minutes, not 7 hours 25 minutes.
Forgetting the clock change. On the night the clocks go back, a shift from 22:00 to 06:00 lasts nine real hours, and on the night they go forward it lasts seven. This calculator works from clock times, so adjust by an hour on those two nights.
One span at a time adds up to a whole week of guessing.
If you are working out durations after the fact, the start and end times are already a reconstruction. PomoTodo timestamps the work as it happens and totals the period for your client by client, ready to invoice.
Free plan tracks unlimited focus time across unlimited tasks. No card required.
More tools
Add and subtract hours and minutes. Totals in every format.
Clock in, clock out, breaks, weekly totals and overtime pay.
Convert both ways, with payroll rounding and a full chart.
24 hour to standard time and back, with the full chart.
Questions
How many hours are between two times?
Enter the start time and the end time and the duration appears underneath in hours and minutes, in clock format, and in decimal hours. Nothing to press, the answer updates as you type.
Does it handle overnight shifts past midnight?
Yes. If the end time is earlier in the day than the start time, the span is treated as crossing midnight, 10:00 PM to 6:00 AM comes out as 8 hours, not minus 16.
Can I calculate a duration across several days?
Turn on the multiple days option and date fields appear next to each time. The result then counts every day in between and tells you how many full days the span contains.
Can I take a lunch break off the total?
Enter the break in minutes and it is deducted from the duration. A 9:00 to 5:30 day with a 45 minute break gives 7 hours 45 minutes.