Add or Subtract from a Date

How to add or subtract time from a date

Choose a starting date, pick whether you want to add or subtract, then enter an amount and a unit (days, weeks, months, or years). The resulting date and its day of the week are shown immediately, along with how far it is from today.

How months and years are handled

When you add months or years and the target month is shorter, the date is clamped to the last valid day. For example, January 31 plus one month becomes February 28 (or February 29 in a leap year). This is the standard behaviour used by spreadsheets and calendar apps.

Common uses

• Find a deadline 90 days from today.
• Work out a due date a number of weeks ahead.
• Calculate a date a few years in the past or future for contracts and warranties.