Add Hours to Time Calculator
Add or subtract hours from a time of day, with the result shown in 24-hour and 12-hour format and a note when it crosses midnight into the next or previous day.
Calculator by Toolsloft ↗- New time (24-hour)
- 14:00
- New time (12-hour)
- 2:00 PM
Add hours to a time of day and see the result on both the 24-hour and 12-hour clock. Enter a start time and the number of hours, positive to move forward or negative to move back, and the tool shows the new time and whether it crosses into another day. Useful for shift planning, travel, and cooking timers.
How this is calculated
The start time is converted to minutes past midnight, the added hours are turned into minutes and applied, and the total is wrapped back into a single day. The day offset is the number of whole days the result moves from the start, found by floor division by the 1,440 minutes in a day.
How to use
- Enter the start time as HH:MM in 24-hour format.
- Enter the number of hours to add, or a negative number to subtract.
- Read the new time and whether it lands on a different day.
Examples
- Same day:
09:00 plus 5 hours is 14:00 - Into next day:
22:00 plus 5 hours is 03:00 the next day - Back a day:
02:00 minus 5 hours is 21:00 the previous day
FAQ
- What does the day offset mean?
- It shows how many whole days the result moves from your start time. A day offset of 1 means the result is on the next day, and -1 means the previous day, which happens when the addition crosses midnight.
- Can I subtract hours?
- Yes. Enter a negative number of hours to go back in time. For example, 02:00 minus 5 hours gives 21:00 on the previous day.