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Time Calculator - Add/ Subtract

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Our online tools will provide quick answers to your calculation and conversion needs. On this page, you can add/ subtract two time durations specified in hours, minutes, and seconds which is very useful for adding hours worked on a project.

Enter time duration as hh:mm:ss

: :

: :

Result window

Time Calculation

Steps for adding time

  • Add the seconds. If the sum is >= 60, subtract 60 and carry forward 1 to minutes addition.
  • Add the minutes and the carry from seconds addition, if any. If the sum is >= 60, subtract 60 and carry forward 1 to hours addition.
  • Add the hours, and the carry from minutes addition, if any.

Steps for subtracting time

  • Subtract the seconds. If the difference is < 0, add 60 to it borrowing 1 from the minutes.
  • Subtract the minutes after regrouping, if there was a borrow in the previous step. If the difference is < 0, add 60 to it borrowing 1 from the hours.
  • Subtract the hours after regrouping, if there was a borrow in the previous step.

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