Add / Subtract Time

Add or subtract hours, minutes, and seconds from a time of day, with automatic wraparound at midnight. Free and private, right in your browser.

Use negative numbers for hours/minutes/seconds to subtract time.

Enter a starting time, then add or subtract any number of hours and minutes to instantly get the resulting clock time - handy for figuring out shift end times, layover arrivals, cooking or medication schedules, or "what time will it be in 6 hours 45 minutes" without doing the math by hand.

How to use it

  1. Enter your starting time
  2. Choose add or subtract and enter hours/minutes to shift by
  3. Read the resulting clock time instantly

Frequently asked questions

Does this account for AM/PM and midnight rollover?
Yes. If adding or subtracting time crosses midnight, the result automatically wraps to the correct time and shows whether it lands on the next or previous day.
Can I subtract time instead of adding it?
Yes, just switch to subtract mode (or enter a negative value) and it will calculate the earlier time the same way.
What format does the result show?
You'll get both 12-hour (AM/PM) and 24-hour clock formats, so you can use whichever matches your schedule, timesheet, or system.