Find the date a chosen number of calendar days before or after another date. Enter a start date, choose Add or Subtract, and calculate immediately.
Free to use. Calculations stay in this browser; no account is needed.
Your result and counting rules
Enter your dates and calculate. The current rule will appear with the result.
How day addition and subtraction work
The starting date is day 0. Adding 1 day moves to the next calendar date; subtracting 1 day moves to the previous date. Adding or subtracting 0 returns the same date. This page adjusts days only; the Time Tools hub also retains its years, months and weeks controls.
Worked example
Start at 2024-12-31 and add 60 calendar days: the result is 2025-03-01, a Saturday. Subtract 1 day from 2024-03-01 to get 2024-02-29, a Thursday.
Boundaries and limitations
Weekends and holidays are counted because this is calendar-day arithmetic. A date alone does not establish a legal, payroll or contractual deadline, which may use a different counting convention. Inputs and results must stay between years 0001 and 9999.
Dates use Gregorian calendar rules and a date-only day index, not local midnight timestamps. Daylight-saving changes cannot add or remove a calendar day.