Time
Time Duration Calculator
Measure the time between two clock times, or add and subtract hours and minutes from a starting time.
Duration
8h 30m
8.5 hours · 510 minutes
Total hours8.5
Total minutes510
How it works
Time durations are computed in minutes from the 24-hour clock. When the end time is earlier than the start time and the "crosses midnight" toggle is enabled, we add 24 hours so an overnight shift like 22:00 → 06:00 returns 8 hours.
Add and subtract mode wraps around the 24-hour clock and labels the result as previous day, same day, or next day so payroll and shift calculations stay accurate.
Frequently asked questions
- How do I calculate hours worked across midnight?
- Enter the start and end times, then enable the 'crosses midnight' toggle. The calculator adds 24 hours so the duration is correct.
- Why does my duration show as negative?
- The end time is earlier than the start. Either swap them or enable 'crosses midnight' if the shift continues into the next day.
- Can I subtract time from a clock time?
- Yes — use Add / Subtract mode. Negative results wrap around to the previous day automatically.