Add or Subtract Days from a Date | Date Calculator
Easily add or subtract years, months, weeks, or days from a given date to find a future or past date.
Result Date
Please provide a valid start date.
About Date Addition & Subtraction
Calendar Math
Adding 1 month to January 31 usually results in February 28 (or 29 in a leap year). The math snaps to the end of the target month if the result would exceed the number of days in that month.
Weeks vs Days
Adding 1 week is always exactly equivalent to adding 7 days. Modifying months or years depends on the calendar boundaries.
Timezones and Daylight Saving Time (DST)
When adding days across DST transitions (e.g., Spring Forward or Fall Back), the wall-clock time remains the same, but the absolute duration in hours might be 23 or 25 instead of 24.