Add or subtract time calculator
Useful for working out when a task ends or when you need to start. The result is shown in 24-hour and 12-hour format with any day change.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter start time, operation, hours and minutes.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Result = start ± (hours × 60 + minutes) in minutes. The remainder after dividing by 1440 gives the clock time and the whole quotient gives the day change.
Example
Inputs: Start time = 09:00, Operation = Add, Hours = 2, Minutes = 30. Result: Resulting time (24-hour): 11:30; 12-hour format: 11:30 AM; Day: Same day.
Limits and caveats
- Works on the clock only and does not show a date; the day change tells you how many days you moved.
- Daylight saving clock changes are not taken into account.
Questions about this tool
What time is it 5 hours after 9 PM?
Enter 21:00 and add 5 hours; the result is 02:00 on the next day.
Can I enter more than 59 minutes?
Yes. Typing 90 minutes, for example, counts as an hour and a half.
What does +2 days mean?
The resulting time falls two days after the day you started from.