How to Calculate an Overnight Shift
An overnight shift begins on one calendar day and ends on the next. The key is to include the time after midnight instead of treating the clock-out time as earlier than the clock-in time.
Practical timekeeping guide · ShiftHours
Example: 10 PM to 6 AM
From 10:00 PM to midnight is two hours. From midnight to 6:00 AM is six hours. Together, the shift lasts eight hours before breaks.
Subtract the unpaid break
If you take a 30-minute unpaid break during the shift, subtract 30 minutes from eight hours. The net duration is 7 hours and 30 minutes, or 7.50 decimal hours.
A general calculation method
Convert the start and end times to minutes after midnight. If the end time is earlier than the start time, add 1,440 minutes to the end time to account for the next day. Subtract the start, then subtract the unpaid break.
Remember date and payroll boundaries
A shift that crosses midnight may fall on two calendar dates, and payroll systems may have specific rules for workdays, overtime, or shift differentials. A simple duration calculator does not determine those pay rules.
Calculate your shift
Use the ShiftHours calculator and select the overnight option if your shift ends the next day. Review the result and confirm that your break entry matches your workplace’s timekeeping policy.
Use the free ShiftHours work hours calculator to subtract unpaid breaks and see your total in hours and decimal format.
Worked example: cross midnight
For a shift from 9:30 PM to 5:30 AM the following day, count 2.5 hours to midnight and another 5.5 hours after midnight. The total is 8 hours before breaks. A 30-minute unpaid break leaves 7.5 hours.
Related resources
Calculate an overnight shift More overnight shift examples Add shifts into a weekly total