Clock Duration Calculator — Time Between Two Times
Find out how long the gap is between two times of day — in hours, minutes and decimal hours.
h
min
h
min
Overnight span
8 h 30 min ≈ 8.5 hours
- 1
Start time in minutes
9 × 60 + 0 = 540 - 2
End time in minutes
17 × 60 + 30 = 1,050 - 3
Duration
1,050 − 540 = 510
How does this calculator work?
Convert both times to total minutes from midnight (hours × 60 + minutes), subtract start from end, and add 1440 if the span crosses midnight. The result in minutes is divided by 60 for decimal hours, or split into whole hours plus a minute remainder.
Formula
How this is calculated
Time on a 24-hour clock is easiest to compare in total minutes from midnight. The calculator converts the start time to minutes (hours × 60 + minutes) and does the same for the end time, then subtracts the start from the end. The result is the elapsed duration in minutes, which is split back into whole hours and a remainder of minutes. Decimal hours are the total minutes divided by 60.
When the end time is earlier in the day than the start — for example, a night-shift worker starting at 22:00 and finishing at 06:30 — the span straddles midnight. Auto-detect mode notices that the end total is less than or equal to the start total and adds 1440 minutes (24 hours) to the end before subtracting, giving the correct overnight duration. You can override this with "Same day" or "Overnight" if the auto-detection does not match your situation.
This tool does not account for time-zone changes, daylight-saving transitions, or calendar dates. Both times are treated as falling within the same 24-hour window (or adjacent windows for overnight). For spans longer than 24 hours, use a date-difference calculator.
Frequently asked questions
Convert each time to total minutes from midnight (hours × 60 + minutes), subtract the start from the end, then divide by 60. For example, 9:00 to 17:30 is (17 × 60 + 30) − (9 × 60) = 1050 − 540 = 510 minutes = 8.5 hours.
If the end time in total minutes is less than or equal to the start time, the calculator assumes midnight was crossed and adds 24 hours (1440 minutes) to the end. Toggle "Same day" to force no overnight, or "Overnight" to always add 24 hours.
Yes — enter your shift start and end times and read the decimal hours result. Multiply decimal hours by your hourly rate to get pay for that shift. Use the overnight option for night shifts.
TG we-Calculate Editorial Team. (2026). Clock Duration Calculator — Time Between Two Times [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/clock-duration-calculator
TG we-Calculate Editorial Team. "Clock Duration Calculator — Time Between Two Times." TG we-Calculate. 2026. https://we-calculate.com/calculator/clock-duration-calculator.
TG we-Calculate Editorial Team, "Clock Duration Calculator — Time Between Two Times," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/clock-duration-calculator
@misc{wecalculate_clock_duration_calculator, title = {Clock Duration Calculator — Time Between Two Times}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/clock-duration-calculator}}, year = {2026}, note = {TG we-Calculate} }
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