How does the DATEDIFF function work in tableau

Recipe Objective - How does the DATEDIFF function work in tableau?

DATEDIFF Function in tableau returns the difference between the "start_date" and "end_date" where "start_date" is subtracted from "end_date". The difference of dates is based upon the "date_part." For example, if we use "month," the function will return the difference between months.

Syntax of DATEDIFF Function:

DATEDIFF(date_part, start_date, end_date, [start_of_week]). "[start_of_week]" is optional.

Example : DATEDIFF('year', #2021-04-15#, #2020-07-13#) = -1