Find the duration between two clock times in hours, minutes, and seconds - overnight spans included.
If the end time is earlier than the start time, the duration crosses midnight into the next day.
Example: Enter 09:00 as the start time and 17:30 as the end time - the result is 8h 30m, which is 8.5 decimal hours and 510 total minutes.
Time Duration Calculator finds how much time passes between two times of the day. Enter a start time and an end time and it reports the span in hours, minutes, and seconds, plus decimal hours for quick arithmetic. When the end time falls before the start time, the calculator understands that the period runs past midnight and counts into the next day. See also: the date and time duration calculator for spans with full dates, or the time calculator to add or subtract a duration.
Both times are converted to seconds from midnight, and the difference is taken. A negative difference means the end time comes earlier on the clock, so 86,400 seconds (one full day) is added to produce the overnight duration. The seconds total is then split back into hours, minutes, and seconds and divided by 3,600 for the decimal-hours figure. Everything runs locally the moment you press the button.
It measures the span between two clock times of the day and reports the result in hours, minutes, and seconds, plus decimal hours. If the end time is earlier than the start time, the duration automatically runs past midnight into the next day.
Enter the times exactly as they appear on the clock, for example 22:30 as the start and 07:15 as the end. Because the end time is earlier than the start time, the calculator adds a full day and reports the overnight span, which in that example is 8 hours and 45 minutes.
Yes - it is completely free with no account required. The calculation runs entirely in your browser, so your inputs never leave your device.
A validation message appears instead of a result - for example, the calculator asks for both a start and an end time, or for clock times within hours 0-23, minutes 0-59, and seconds 0-59. Correct the field and press Calculate Duration again.
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