How to use this tool
Enter two durations as hours:minutes or hours:minutes:seconds. Hours can exceed 23; minutes and seconds must each be from 00 to 59. Choose addition or subtraction. The answer is elapsed-duration arithmetic and does not involve dates, time zones, daylight saving changes or midnight rollover.
Try these values
1:45:00 + 0:30:00 = 2:15:00, or 2.25 decimal hours. Subtracting a longer duration produces a negative result.
Common questions
Can I enter 27 hours?
Yes. 27:00:00 is a valid duration even though 27:00 is not a time on a 24-hour clock.
Is 1:30 equal to 1.30 hours?
No. 1:30 is one hour and thirty minutes, equal to 1.5 decimal hours.
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