Time Duration Calculator
Use this free time duration calculator to work out the hours, minutes and days between two times or two dates — fast and exact.
Enter a start time and an end time to see the duration.
How to use this time duration calculator
Step 1: Choose Times or Dates at the top of the calculator. Times is for working out the hours and minutes between two clock times, such as a shift, a flight or a meeting. Dates is for working out the days between two calendar dates, such as a holiday, a deadline or a project.
Step 2: Enter the start and the end. In Times mode, pick the start time and the end time from the time pickers. In Dates mode, pick the start date and the end date from the date pickers. If the time runs past midnight, tick the Ends next day box — see the section below.
Step 3: Read the result, which updates live. In Times mode you get the duration in hours and minutes, plus the total minutes and total seconds. In Dates mode you also get the total days and the same span in weeks and days, so you can see at a glance whether it is closer to two weeks or a full month.
Worked example: 09:30 to 17:45
Take a working day that starts at 09:30 and ends at 17:45. First, work out the hours. From 09:30 to 17:30 is 8 hours exactly. Then add the extra 15 minutes from 17:30 to 17:45. The duration is 8h 15m.
To check it in minutes, turn both times into minutes since midnight. 09:30 is 9 times 60 plus 30, which is 570 minutes. 17:45 is 17 times 60 plus 45, which is 1,065 minutes. Subtract: 1,065 minus 570 is 495 minutes. Divide 495 by 60 and you get 8 hours with 15 minutes left over, which matches. In seconds, 495 minutes times 60 is 29,700 seconds. The time duration calculator does all of this for you, but knowing the steps helps you spot a mistake if you typed a time wrong.
The same method works for any two times. Count the full hours first, then the leftover minutes, and you have the answer. If the end time is a round hour, such as 18:00, there are no leftover minutes at all, and the answer is a whole number of hours.
Times that run past midnight
Some times run past midnight: night shifts, flights, parties and events that start in the evening and finish in the early morning. A plain subtraction gets these wrong, because the end time looks smaller than the start time. A shift from 22:00 to 06:30 looks like minus 15 hours and 30 minutes if you subtract directly, but it is really 8 hours and 30 minutes.
That is what the Ends next day box is for. Tick it and the calculator counts the end time as belonging to the next day, adding 24 hours to it before subtracting. So 06:30 becomes 30 hours and 30 minutes on the same clock, minus 22:00 gives 8h 30m, or 510 minutes. If the box is unticked and the end time is earlier than the start time, the calculator tells you plainly to tick it if the time runs past midnight, instead of showing a negative answer.
Dates
In Dates mode, the tool counts the gap between the dates, so 1 January to 31 January is 30 days — the start day itself is not counted twice. Think of it as counting the steps between two points on a calendar: from the 1st to the 2nd is one day, so from the 1st to the 31st is 30 days.
The weeks figure works the same way. Thirty days is 4 full weeks, which is 28 days, with 2 days left over, so the calculator shows 4 weeks + 2 days. Fourteen days is exactly 2 weeks, with nothing left over, so it says 2 weeks exactly. This is handy for planning time off, counting down to an event, or working out how long a project lasted, because weeks are often easier to picture than a bare number of days.
Frequently asked questions
How do I count hours between two times?
Pick Times mode, enter the start time and the end time, and the calculator shows the duration in hours and minutes, plus the total minutes and total seconds. For example, 09:30 to 17:45 is 8h 15m, or 495 minutes.
What if the time runs past midnight?
Tick the Ends next day box. The end time is then counted as the next day, so 22:00 to 06:30 gives 8h 30m. Without the box ticked, the calculator warns you that the end time is earlier than the start time.
How many days are between two dates?
Pick Dates mode and enter both dates. 1 January 2026 to 31 January 2026 is 30 days, and 1 March 2026 to 15 March 2026 is 14 days, which is exactly 2 weeks.
Does it count the start day?
No — it counts the gap between the dates, so Jan 1 to Jan 31 is 30 days, not 31. The start day is the starting point, and the first day counted is the day after it.
Is the result exact?
Yes — it is exact calendar maths, with no rounding. Hours, minutes and seconds are worked out from the times you entered, and days are counted on the calendar, including months of different lengths.