Time Calculator
Add or subtract hours and minutes, multiply a duration, find an overnight difference, or move a clock time forward and back.
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| Step | Input | Meaning |
|---|
Hours and minutes, with the working shown
Add a list of task durations or subtract a break by putting a minus sign before it. For example, 1:30 plus 0:45 minus 0:15 is 2:00:00. Blank lines are ignored, and an invalid line is identified so it can be corrected.
Multiply, divide or cross midnight
A 1:30 duration multiplied by 3 is 4:30:00. Dividing one hour by 8 gives 0:07:30. For an overnight span from 22:30 to 06:15, select an ending-day offset of 1: the result is 7:45:00. Adding 2:30 to 23:15 gives 01:45:00 on the following date.
Does this account for daylight saving or work breaks?
These are duration and clock calculations on fixed 24-hour days. They do not infer dates, zones, payroll rounding or breaks. Use the dated time-zone converter for local clock changes, the Work Hours Calculator for shifts and breaks, or the Date Calculator for calendar dates.
How much precision is kept?
Durations and results keep milliseconds. Numeric duration units accept up to nine decimal places; multiplication and division factors accept six. Values are rounded to the nearest millisecond when needed, with exact halves away from zero. Decimal totals show up to six places. Each duration and the final result must stay within 1,000,000 hours in either direction.