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Date Calculator: Add or Subtract Days
Find the date that's a number of days, weeks, months or years before or after any date, with correct month-end handling.
Tip from Tink: 90 days is not 3 months: months have different lengths.
Result
Sat, January 31, 2026
Adding a month to the 31st lands on the last day of a shorter month (Jan 31 + 1 month = Feb 28 or 29).
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How to use the Date Calculator: Add or Subtract Days
- Pick a start date.
- Choose add or subtract.
- Enter years, months, weeks and days.
Everything runs in your browser. Nothing you enter is uploaded.