Add Time Calculator
Add or subtract hours, minutes and seconds from a starting time of day.
Resulting time
11:30:00
11:30:00 AM
About the Add Time Calculator
The Add Time Calculator takes a starting clock time and adds or subtracts a duration given in hours, minutes and seconds. The result is a normal 24-hour clock time plus a friendly 12-hour version.
When the total crosses midnight the tool reports how many days forward or back the result lands, so an addition that rolls past midnight is never confusing.
This is useful for shift planning, cooking timers, travel schedules and any situation where you need to add a block of time to a start time without doing the arithmetic by hand.
Key features
- Add or subtract hours, minutes and seconds
- 24-hour and 12-hour result display
- Next-day and previous-day roll-over labels
- Instant recalculation as you type
How to use
- 1Enter the start time of day.
- 2Choose Add or Subtract.
- 3Enter the hours, minutes and seconds to apply and read the resulting time.
Examples
09:00:00 + 2h 30m11:30:00The duration is added to the start time to give the new clock time.
23:30:00 + 1h00:30:00 (next day)Adding past midnight wraps the clock and flags the next day.
Frequently asked questions
- What happens if the result goes past midnight?
- The tool wraps the clock correctly and shows a label such as next day or previous day, along with the number of days shifted for larger amounts.
- Can I add more than 24 hours?
- Yes. You can enter any number of hours, minutes or seconds and the result rolls across as many days as needed.
- Does it use a 12-hour or 24-hour clock?
- You enter the start time in 24-hour form and the result is shown in both 24-hour and 12-hour AM or PM formats.