Cobol??

Answer 1

programmers may need to use their own code and not use a built-in method
01 ws-001date    pic x(10).
01 ws-date2 redefines ws-001date.
02 ws-dd       pic xx.
02 ws-sep1   pic x.
02 ws-mm     pic xx.
02 ws-sep2   pic x.
02 ws-yyyy    pic xxxx.

after obtaining the date into the ws-date then code the validation to include
checks if ws-mm is less than "01" or greater than "12", if the ws-dd is in the range for the calendar month as "01" to "31", or "01" to "30" as appropriate or for February "01" to "28" [or "29" if the year is divisible by 4 with a remainder zero], appropriate range checks for the year and valid characters for the separator items like "-" or "/" or "."