Time Difference Calculator
Calculate a clock-time difference for the same day or the next day, including seconds and decimal hours.
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How to use Time Difference Calculator
Find the duration of a shift, session, or overnight interval. Explicitly choose whether the ending time belongs to the same day or the following day to avoid ambiguous midnight assumptions.
- Enter two 24-hour clock times, optionally including seconds.
- Choose whether the ending time is on the same or following day.
- Calculate the signed duration, decimal hours, minutes, and seconds.
Good to know
- This tool compares clock readings without calendar dates or time zones. Daylight-saving changes and leap seconds are not included.
- The following-day option always adds one day, even when the ending clock time is later. Use Date Difference for calendar spans.
Common questions
How do I calculate an overnight shift?
Enter the starting and ending times and choose Following day. For 22:30 to 01:15, the duration is 2 hours 45 minutes.
Why can the same-day result be negative?
Same day subtracts the start time from the end time directly. An earlier ending time therefore produces a negative interval.
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