How to use this calculator
Choose a clock-time difference, work duration, travel-time calculation or fixed time-zone comparison. Enter the units and times requested by the selected mode.
How to use the result
A clock-time interval that ends before it starts is treated as passing through midnight. Work time subtracts the entered break duration. Travel time is distance divided by speed; distance and speed must use compatible units.
The time-zone mode compares fixed standard-time offsets. Its result is an offset difference, not a date-specific local arrival time.
Assumptions and limits
Clock times do not include calendar dates, so they cannot describe multi-day intervals. Break time cannot exceed the interval. Daylight-saving changes are excluded from the fixed-offset comparison; use a date-aware time-zone service for a flight or meeting.
Worked example
From 22:00 to 06:00 the overnight interval is 8 hours. Subtracting a 30-minute break gives 7 hours 30 minutes of work time.