Date Calculator
Start from any date, then add or subtract a number of days, weeks, months or years to find the target date.
Result date —
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Frequently asked questions
How are months and years added when the date would overflow?
The calculator uses calendar arithmetic, so adding one month to January 31 gives February 28 (or 29 in a leap year) rather than a non-existent February 31. This matches how most calendars and spreadsheet functions behave.
Does subtracting a month keep the same day of month?
It tries to, but rolls back to the last valid day if that day does not exist in the shorter month. For example, subtracting a month from March 31 lands on February 28 (or 29 in a leap year).
Can I use this to find a due date or anniversary?
Yes. Start from the original date, add the number of days, weeks, months or years, and the result is the target date with its weekday shown.