Add or Subtract Days
Enter a starting date and a number of days to add or subtract, and the tool instantly shows you the resulting date. Toggle between adding and subtracting with a single click.
The calculation handles month boundaries, year boundaries, and leap years correctly — adding 60 days to January 15 will land you in mid-March, properly accounting for February's length. Useful for deadline calculations, payment due dates, warranty expiration, and any situation where you need to count forward or backward from a known date.
Everything runs in your browser using standard date arithmetic.
By The Paper Room Editorial Team — Date Tools
Frequently asked questions
Does it handle leap years?▼
Yes. The calculation uses the JavaScript Date object, which correctly handles leap years, varying month lengths, and all calendar edge cases.
Can I add months or years instead of days?▼
This tool works with days specifically. For month or year arithmetic, you can use the Date Difference Calculator to work backward from a known result, or multiply (e.g., 365 days for roughly one year).
What is the maximum number of days I can add?▼
There is no practical limit. You can add or subtract millions of days and the tool will compute the resulting date correctly, as long as it falls within the range JavaScript's Date object supports (roughly 270,000 years in either direction).