Time Duration Calculator · Practical guide
How to Calculate Overnight Shift Hours
Night shifts cross midnight, which breaks ordinary subtraction — here's the fix and a lookup table for common shifts.
At a glance
The Rule for Overnight Shifts
A shift from 10:30 PM to 6:15 AM lasts 7 hours 45 minutes. The trick: when the clock-out time is earlier than the clock-in time, add 24 hours (1,440 minutes) to the end time before subtracting. That is exactly what the assume-next-day option above does for you.
Interactive tool
Time Duration Calculator
Enter your own values, then compare the result with the examples below.
Results
Worked Example Step by Step
- 10:30 PM → 22 × 60 + 30 = 1,350 minutes after midnight
- 6:15 AM → 6 × 60 + 15 = 375 minutes
- 375 + 1,440 = 1,815 (push the end time into the next day)
- 1,815 − 1,350 = 465 minutes = 7 h 45 m
Common Overnight Shifts
| Clock In | Clock Out | Duration |
|---|---|---|
| 11:00 PM | 7:00 AM | 8 hours |
| 10:00 PM | 6:00 AM | 8 hours |
| 7:00 PM | 7:00 AM | 12 hours |
| 11:30 PM | 7:30 AM | 8 hours |
| 6:00 PM | 2:00 AM | 8 hours |
Converting to Decimal for Payroll
Timesheets usually need decimal hours: divide the minutes by 60. A 7 h 45 m shift is 7 + 45 ÷ 60 = 7.75 hours, which at $20 per hour pays $155.00. Deduct unpaid breaks the same way — a 30-minute lunch cuts that shift to 7.25 paid hours, or $145.00.
Frequently Asked Questions
How many hours is 11 PM to 7 AM?
Exactly 8 hours. The span crosses midnight, so the calculator adds 24 hours to the 7 AM end time before subtracting.
Why does 10 PM to 6 AM show 16 hours without the next-day option?
With the option off, the calculator treats both times as the same day and shows the absolute difference — 16 hours — instead of the true overnight span of 8 hours.
How do unpaid breaks work on a night shift?
Calculate the full overnight span first, then subtract the break. An 8-hour overnight shift with a 30-minute unpaid meal break is 7 hours 30 minutes of paid time.
Is there a maximum shift length the calculator handles?
It handles spans up to 23 hours 59 minutes. For anything longer than a day, use a date-based calculator instead.