How it works
To find the time between two clock times, convert both to minutes after midnight and subtract. If the end time is earlier than the start time, the period crosses midnight, so 24 hours (1,440 minutes) is added to the end. Unpaid break minutes are then subtracted.
minutes = (end − start [+ 1,440 if overnight]) − break decimal hours = minutes ÷ 60 · pay = decimal hours × hourly rateWorked example. A shift from 08:30 to 17:15 with a 45-minute lunch: 17:15 is 1,035 minutes after midnight and 08:30 is 510, so the span is 525 minutes; minus 45 = 480 minutes = 8:00 hours. A night shift from 22:00 to 06:30: 390 − 1,320 is negative, so add 1,440 → 510 minutes = 8.5 hours.
Using the 24-hour clock
Enter afternoon times as 13–23: 1:00 pm is 13, 5:15 pm is 17:15, and midnight is 0 (or 24 for “end of day”). This avoids AM/PM mistakes, which are the most common error in time cards.
| 12-hour | 24-hour |
|---|---|
| 12:00 am (midnight) | 00:00 |
| 9:30 am | 09:30 |
| 12:00 pm (noon) | 12:00 |
| 3:45 pm | 15:45 |
| 11:00 pm | 23:00 |
Weekly totals and overtime
Add each day’s decimal hours for the week. Hours above the normal working limit — often 8 a day or 40–48 a week depending on the country — may be paid as overtime; work out the amount with the overtime pay calculator. To add several durations together, use the time calculator.
This tool assumes a shift shorter than 24 hours. Daylight-saving changes (not used in the Gulf countries) can make a night shift one hour longer or shorter.