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, January 2, 1983
Added to Friday, December 3, 1982.
ISO date1983-01-02
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.