Formula
duration = end − start (add 24 hours if the end time is earlier than the start)net duration = duration − breakdecimal hours = minutes ÷ 60
- Times use the 24-hour clock internally and are shown in both formats
Convert both times to minutes since midnight and subtract.
Worked examples
A workday with a break
- What do you want?
- Time between two clock times
- Start time
- 09:00
- End time
- 17:45
- Unpaid break (minutes, optional)
- 30
Net duration
8 h 15 min
In decimal hours: 8.25 hours
In minutes: 495
Before the break: 8 h 45 min
Add 3 h 45 min to 22:30
- What do you want?
- Add or subtract a duration
- Starting time
- 22:30
- Operation
- Add
- Hours
- 3
- Minutes
- 45
Resulting time
02:15 (2:15 AM)
Day: next day
Duration applied: +3 h 45 min
How it works
To find the time between two clock times, convert each to minutes since midnight and subtract. From 09:00 to 17:45 is 8 hours 45 minutes, and with a 30-minute unpaid break the working time is 8 hours 15 minutes, or 8.25 in decimal hours — the figure most timesheets and payroll systems need.
If the end time is earlier than the start time the calculator assumes you worked past midnight and adds 24 hours, so 22:00 to 06:00 is 8 hours. In the other mode you add or subtract a duration from a time and see the result along with how many days forward or back it landed: 22:30 plus 3 hours 45 minutes is 02:15 on the next day.
This works with clock times only and does not know about dates or daylight-saving changes. For spans across calendar dates use the Days Between Dates Calculator or the Date Calculator: Add or Subtract Time; for overtime pay on the extra hours see the Overtime Pay Calculator, and for another city's clock the Time Zone Converter.
Assumptions and limits
- Clock times only: daylight-saving changes and dates are not considered.
- If the end time is earlier than the start time, it is taken to be on the next day.