Two calculators in one
Duration between date-times: enter a start date and time and an end date and time. The calculator shows the duration as days, hours and minutes, and as totals in minutes, hours, days and seconds. From 9:00 on a Monday to 17:30 on the Wednesday is 2 days, 8 hours and 30 minutes, or 56.5 hours.
Add or subtract time: enter a starting date and time and the number of days, hours and minutes to add or subtract. The result is the new date and time, with day and month changes handled automatically — 20 hours after 22:00 is 18:00 the next day.
How times are handled
Times use the 24-hour clock (00:00 to 23:59). The calculator treats each day as exactly 24 hours and does not apply time-zone or daylight-saving changes, so durations that cross a daylight-saving switch in your location may be an hour different from wall-clock time. For whole-day calculations, use the Date to Date Calculator or the Days Between Dates counter.
Examples
- Shift length from 22:00 to 06:30 the next day: 8 hours 30 minutes.
- A 72-hour return window starting at 15:00 on Friday ends at 15:00 on Monday.
- A 36-hour fast starting at 20:00 on Sunday ends at 08:00 on Tuesday.
Converting between days, hours and minutes
One day is 24 hours, 1,440 minutes or 86,400 seconds; one week is 168 hours. To turn a decimal number of hours into hours and minutes, multiply the decimal part by 60 — 7.75 hours is 7 hours 45 minutes. The calculator shows every duration both ways so you can copy whichever format your timesheet, invoice or booking needs.