Add or subtract dates
Move a date by calendar units. Years are applied first, then months, then weeks and days; invalid month-end dates clamp to that month’s final day.
Sunday, April 2, 1989
Added to Friday, March 3, 1989.
ISO date1989-04-02
WeekdaySunday
Absolute day distance30
Month-end clamping happens after years and again after months. For example, subtracting one month from March 31 lands on February 28 or 29.