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ADAAT

Date Calculator

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Enter a start and end date to see the gap in days, weeks, months, and years — or add days and months to a date to find a future deadline.

How to use

  1. 1Choose "difference between two dates" or "add/subtract a duration".
  2. 2Enter the dates or the duration.
  3. 3The result appears in multiple formats.

Features

  • Difference in days, weeks, months, and years
  • Add or subtract days, months, and years
  • Leap years accounted for

When to use this tool

Use it to measure a project or leave period, to work out a due date a set number of days out, to track age in weeks, or to compare two meaningful dates.

FAQ

Is the starting day included in the difference?

We show the net difference between the two dates; add one day if you want to count the starting day.