Clock and hours · rules read October 11, 2026
Hours between two times
Type when the shift starts and when it ends, on the 12-hour or 24-hour clock; the calculator counts the hours, even past midnight.
Written by Radif Partners · How the hours are counted · Editorial policy
Hours worked
8:00
8.00 decimal hours
| Start | 9:00 AM → 9:00 AM |
| End | 5:30 PM → 5:30 PM |
| Same times on the 24-hour clock | 09:00 to 17:30 |
| Time at work before the break | 8:30 |
| Exact minutes worked (no rounding) | 8:00 |
Rounding is accepted only if it averages out over time and does not shortchange the worker (29 CFR 785.48(b)). A shift that ends at or before its start time is counted into the next day. How this is calculated.
To find the hours between two times, subtract the start from the end and, when the end is earlier on the clock than the start, add 24 hours because the shift ran past midnight. A night shift from 10:00 PM to 6:30 AM lasts 8:30, and with an unpaid meal of 30 minutes taken off it leaves 8:00 worked, or 8.00 decimal hours for payroll. Federal rules decide which breaks may be removed: a bona fide meal period, ordinarily 30 minutes or longer with no duties, is not work time under 29 CFR 785.19, while rest breaks of 5 to 20 minutes count as hours worked under 785.18 and stay on the total. The calculator reads 12-hour times with AM or PM and 24-hour times such as 22:00, shows the result in hours and minutes and in decimal, and never asks you to sign up.
Hours between two times, night shifts included
Hours worked
8:00 (8.00 h)
| From | 10:00 PM |
| To | 6:30 AM, next day |
| Before the break | 8:30 |
Common shifts, already counted
The table below was produced by the same clock arithmetic as the calculator. Each row starts from a start time, an end time and a meal break, and gives the time on the premises, the hours to pay and their decimal form. Where the break column reads 0, the shift has only paid rest breaks, which stay on the total. The two overnight rows show what trips up most people counting by hand: the end time is smaller than the start, yet the shift is a normal length.
| Start | End | Meal break | Span | Hours worked | Decimal |
|---|---|---|---|---|---|
| 7:00 AM | 3:30 PM | 30 min | 8:30 | 8:00 | 8.00 |
| 8:00 AM | 5:00 PM | 60 min | 9:00 | 8:00 | 8.00 |
| 9:00 AM | 5:30 PM | 30 min | 8:30 | 8:00 | 8.00 |
| 6:00 AM | 2:00 PM | none | 8:00 | 8:00 | 8.00 |
| 11:00 AM | 7:45 PM | 30 min | 8:45 | 8:15 | 8.25 |
| 3:00 PM | 11:30 PM | 30 min | 8:30 | 8:00 | 8.00 |
| 7:00 PM | 7:30 AM (next day) | 30 min | 12:30 | 12:00 | 12.00 |
| 11:00 PM | 7:00 AM (next day) | none | 8:00 | 8:00 | 8.00 |
A twelve-hour night from 7:00 PM to 7:30 AM with a 30-minute meal is a good example of why the span and the paid hours differ. The worker is on site for 12:30, but the meal is not work time if it was genuinely free, so 12:00 go on the time card. Whether some of those hours are overtime depends on the rest of the week, or on the day itself in California, Alaska, Nevada and Colorado; the overtime calculator takes over from there.
Counting by hand: borrowing 60 minutes
Clock times are not decimal numbers, which is why a plain subtraction on a phone calculator gives nonsense. Take a day from 8:40 AM to 4:15 PM. First move the end to the 24-hour clock: 4:15 PM is 16:15. Then subtract the minutes: 15 minus 40 does not go, so borrow one hour from the 16 and add 60 minutes to the 15. The end becomes 15 hours and 75 minutes. Now 75 minus 40 leaves 35 minutes, and 15 minus 8 leaves 7 hours. The answer is 7:35, which matches the calculator.
For a night shift, the extra step is adding 24 to the end hour when it is smaller than the start. From 22:00 to 06:30, the end becomes 30:30, and 30:30 minus 22:00 is 8:30. Some people prefer splitting at midnight instead, counting the hours left in the evening and then the hours of the morning; both give the same figure. Do the break last, once the span is known, so the borrowing stays simple.
The habit that causes the most mistakes is reading 4:15 PM minus 8:40 AM as 4.15 minus 8.40 in decimals. It returns a negative number, and even after adding twelve it gives 7.75, which looks believable but is ten minutes too long. The hours and minutes converter explains where the 0.75 versus 0.58 confusion comes from.
12-hour or 24-hour times, and which breaks to remove
The calculator understands 7:15pm, 7:15 PM, 1915 and 19:15, and treats a time typed with no AM or PM as 24-hour time. Hospitals, police departments and many warehouses already schedule in 24-hour form, and the military time converter turns any value into the four-digit style those rosters use. On the 12-hour clock, the only ambiguous points are 12:00 AM, which is midnight, and 12:00 PM, which is noon.
For breaks, the federal line is set in the Department of Labor Fact Sheet #22: the FLSA itself does not require any break, but when an employer offers short ones, they are paid. Under 29 CFR 785.18 a rest of about 5 to 20 minutes counts as work, and under 29 CFR 785.19 a meal of 30 minutes or more can be unpaid only if the employee is completely relieved. A cashier who eats at the register is still working. Put the meal length in the break field and leave coffee breaks out. The meal and rest break guide lists the stricter state rules, such as California's meal after 5 hours.
To log a whole week instead of a single shift, the weekly time card on the home page repeats this calculation for seven days and adds the overtime split.