How to Calculate Overnight Shift Hours

Worked examples across midnight

22:00–06:00: (24:00 − 22:00) + 06:00 = 8:00. Subtract a 30-minute unpaid meal and the result is 7:30, or 7.50 hours. From 23:30 to 02:15, the elapsed time is 0:30 + 2:15 = 2:45, or 2.75 hours.

If you record 22:00–02:00 and 02:30–06:00 as two periods, the total is already 7:30. Do not also enter the 02:00–02:30 gap as a lunch deduction.

Use explicit clock inputs

1. Enter 10:00PM and 6:00AM, or 22:00 and 06:00. Avoid an ambiguous “6” when you intend evening.
2. The calculator interprets an end earlier than its start as the next day. An equal start and end represents zero elapsed minutes, not a 24-hour shift.
3. Enter only unpaid time inside the recorded periods in Break or Lunch.
4. Check Daily Total in H:MM and decimal hours. Use the clock converter to check notation if needed.

Daylight saving and timezone limitations

The current clock-span calculation does not attach a timezone or UTC offset to each punch. On a daylight saving transition, actual elapsed time can differ from the wall-clock subtraction by an hour or another local offset change. Confirm the real start/end timestamps independently rather than treating the displayed span as an automatic DST adjustment.

A date shown on a record does not add timezone awareness to the clock inputs. A single start/end pair also cannot distinguish an eight-hour shift from one lasting 32 hours with the same clock endpoints. Split long work into dated records appropriate to the actual schedule.

A shift can also cross an overtime workweek

Midnight is not necessarily the employer’s workweek boundary. If a shift crosses that recurring boundary, its hours may need to be allocated to different workweeks. The basic weekly table groups rows; it does not automatically determine a legal boundary time or split a shift at it.

Check the workweek described in DOL Fact Sheet 23 where U.S. federal rules apply. See the overtime guide and hours-worked guide for the surrounding calculation.