Add Days to a Date
Add or subtract days, weeks, months or years from a date.
negative numbers go backwards
Good to know
How should I write the starting date?
Use year-month-day, such as 2026-09-05, then choose how many days, weeks, months or years to add. A negative amount moves backwards.
What happens near the end of a month?
Calendar months have different lengths. If the same day does not exist in the destination month, the date can roll into the following month. Check the result for month-end dates.