Split the shift at midnight
When the end time is earlier than the start time, the end usually belongs to the next day. Break the shift into the time before midnight and the time after midnight, then add the two parts.
10:00 PM to 6:00 AM
There are 2 hours before midnight and 6 hours after midnight. The elapsed shift is 8 hours. After a 30-minute unpaid break, the worked result is 7 hours 30 minutes, or 7.50 decimal hours.
The same example in 24-hour time
22:00 to 24:00 is 2 hours. 00:00 to 06:00 is 6 hours. Add them to get 8 hours before breaks. Compact workplace notation may write the same endpoints as 2200 and 0600.
| Notation | Start | End next day | Elapsed |
|---|---|---|---|
| 12-hour | 10:00 PM | 6:00 AM | 8h |
| 24-hour | 22:00 | 06:00 | 8h |
Avoid the 16-hour subtraction error
Subtracting 22 from 6 gives a negative number because the clock reset at midnight. Add 24 hours to the next-day end before subtracting: (6 + 24) − 22 = 8. Equal start and end times remain ambiguous; record dates or split the entry instead of assuming a 24-hour shift.