Time Add and Subtract Calculator
Shift work, cooking and travel planning: add or subtract any hours, minutes and seconds from a starting clock time and see the result, including day changes.
Enter a start time and an amount to add or subtract.
How to use
- Set the starting clock time.
- Choose Add or Subtract and enter hours, minutes and seconds.
- Read the resulting time in 24 hour and 12 hour format, with any day shift noted.
Carry is handled exactly like a clock: 60 seconds make a minute and 60 minutes make an hour, and results past midnight roll into the next day (shown as plus 1 day).
Good to know
- Results show both 24-hour and 12-hour formats, with a "+1 day" note when you cross midnight.
- Useful for shift planning: add 8 hours 30 minutes to a 22:00 start to land at 06:30 the next day.
- Seconds carry over exactly like a real clock: 60 seconds make a minute, 60 minutes an hour.