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Date Add/Subtract Calculator
Add or subtract days, weeks, months, or years from any date. Handles month-end and leap-year edge cases automatically.
Quick presets
Sunday, September 6, 2026
30 days after your start date
How it works
- 1Pick a start date
Choose any date: today, a birthday, a deadline.
- 2Choose add or subtract
Add moves forward in time; subtract moves backward.
- 3Set the amount
Enter a number and pick days, weeks, months, or years.
Frequently asked questions
What happens when I add months to January 31?
The result is clamped to the last valid day of the resulting month (e.g. Feb 28 or 29).
Does this account for leap years?
Yes. Adding one year to Feb 29 on a leap year gives Feb 28 on a non-leap year.
Can I calculate dates far in the future or past?
Yes, any number of days, weeks, months, or years works.
What does "subtract" mean here?
Subtracting moves the date backward. Subtracting 30 days from today gives the date 30 days ago.
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