Time Duration Calculator
Find the duration between two clock times, add or subtract hours and minutes, convert duration units, or calculate net work time after breaks. Overnight time ranges are handled automatically.
How does the time duration calculator work?
This calculator compares clock times without timezone conversion. In “Automatic” day handling, when the end time is earlier than the start time, the end is treated as the following day. That makes 23:30 to 02:00 equal to 2 hours 30 minutes.
Work hours and break time
Work Hours mode first calculates the gross shift duration, then subtracts break minutes. When a daily target is entered, the difference between net work time and the target is shown as overtime or shortfall.
Hours, minutes and seconds conversion
Conversion mode uses 1 hour = 60 minutes = 3,600 seconds and 1 day = 24 hours. “Day” here is a duration unit, not a calendar or business day.
Frequently Asked Questions
How do I calculate the duration between two times?
Enter the start and end clock times. With Automatic day handling, an end time earlier than the start time is treated as the following day.
How long is 23:30 to 02:00?
With Automatic day handling, the duration is 2 hours 30 minutes. Same Day is available when the two times must belong to one calendar day.
How many hours is 135 minutes?
135 minutes equals 2 hours 15 minutes, or 2.25 hours in decimal form.
Does the work-hours mode subtract breaks?
Yes. Work Hours mode subtracts the break minutes you enter from the gross shift duration to calculate net work time.