Date Add/Subtract Calculator
Add or subtract days, months, or years from a date — instantly, in your browser.
Runs in your browser
Private & secure
Add or subtract days, months, or years from a date. Enter a starting date and an amount below — the result updates instantly, entirely in your browser.
How it works
Adding or subtracting months and years correctly rolls over month and year boundaries — for example, adding 3 months to November 15 gives February 15 of the following year, not an invalid date.
FAQs
What happens if the resulting day doesn’t exist in the target month?
JavaScript’s date handling rolls the date forward into the next month in that case (for example, adding 1 month to January 31 can land on March 2 or 3 depending on February’s length) — a known edge case of calendar math with variable month lengths, not unique to this tool.