Time calculator
Shift a time, total your work hours, and convert time units.
This tool does not calculate dates. A day is 24 hours; time zones and daylight saving time are not included.
Add or subtract time
Total multiple intervals
Intervals with the same day number are grouped. An end earlier than the start means the next day and counts toward the starting day. Equal times mean zero hours; overlapping intervals are added separately.
Time ↔ decimal conversion
Usage and limits
- Results appear in hours, minutes, and seconds and in HH:MM:SS. Negative durations have a leading minus sign; clock day offsets appear as +1 or -1 days.
- The absolute duration or result must not exceed 999999999:59:59. Enter minutes and seconds from 00 to 59.
- Decimal output is approximate, rounded to at most 6 decimal places. Breaks are also rounded to the nearest second before subtraction.
- Each interval is less than 24 hours. Split shifts of 24 hours or more into multiple intervals. Overlapping intervals are not automatically merged or deduplicated.
- Input and results are never saved or transmitted. Reloading resets them.