How to use the Time Duration calculator
- Enter your numbers. Fill in start date, start time, end date, end time.
- Read your results. Results update instantly. The headline shows the duration; the breakdown below show the details.
How it works
Enter a start and end time (and optionally dates). The calculator converts both to minutes, subtracts and shows the difference as hours and minutes, decimal hours, and total minutes.
Decimal hours for payroll
Timesheets often need decimal hours: divide minutes by 60. 7 hours 45 minutes is 7.75 hours; 8 hours 20 minutes is 8.33 hours. Subtract any unpaid breaks yourself before multiplying by your hourly rate.
Overnight shifts
If a shift runs from 10:00 PM to 6:30 AM, the end time is earlier than the start, so the calculator assumes it ends the next day: 8 hours 30 minutes.
Daylight saving time
This calculator measures clock time: the difference between the times shown on the clock. If the span crosses a daylight saving change, actual elapsed time differs by one hour. For example, 10:00 PM on March 7, 2026 to 6:00 AM on March 8, 2026 shows 8 hours, but only 7 hours actually pass in U.S. time zones that “spring forward” that night (and a night when clocks “fall back” has one extra hour). For DST-aware times across locations, use the Time Zone Converter.
Worked example
With these inputs: start date 2026-10-12; start time 09:00; end date 2026-10-14; end time 17:30.
The calculator gives a duration of 2d 8h 30m. Other results: total hours 56.50, total minutes 3,390, total seconds 203,400, decimal days 2.354.
What your results mean
The duration is the elapsed clock time between start and end. Decimal hours are what most payroll systems need.
Tips
- Use 24-hour time to avoid AM/PM mistakes.
- Add dates for spans longer than a day.
- Round as your employer’s policy allows, often to the nearest 15 minutes.
Frequently asked questions
How many hours between 8 AM and 4:30 PM?
8 hours 30 minutes, or 8.5 decimal hours.
How do I calculate hours worked?
Subtract start time from end time, then subtract unpaid breaks.
How do I convert minutes to decimal hours?
Divide by 60: 15 min = 0.25, 30 min = 0.5, 45 min = 0.75.
How many hours is 9 AM to 5:30 PM?
8.5 hours, or 8 hours if you take an unpaid 30-minute lunch.
Does it handle daylight saving time?
It measures clock time, not elapsed time. If the span crosses a daylight saving change, the real elapsed time is one hour shorter (spring forward) or longer (fall back) than shown. For DST-aware times, use the Time Zone Converter.
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