Program to validate the date

                                        IDENTIFICATION DIVISION.                              
       PROGRAM-ID.
       ENVIRONMENT DIVISION.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 DATE1.
           02 YEAR PIC 9(4).
           02 MONTH PIC 9(2).
           02 DAY1 PIC 9(2).
       77 ANS PIC 9(4).
       77 REM PIC 9.
       PROCEDURE DIVISION.
       MAIN-PARA.
           DISPLAY "Enter date (yyyymmdd : ".
           ACCEPT DATE1.
           IF (DAY1<1 OR >31) OR (MONTH<1 OR >12) OR (YEAR<0)
               PERFORM INVALID-PARA.
           IF MONTH=2
               DIVIDE YEAR  BY 4 GIVING ANS REMAINDER REM
               IF ((REM NOT =0) AND (DAY1>28)) OR
                            ((REM = 0) AND (DAY1 > 29))
                   PERFORM INVALID-PARA.
           PERFORM VARIFY-PARA.
          VARIFY-PARA.
           IF (MONTH=4 OR 6 OR 9 OR 11) AND (DAY1>30)
               PERFORM INVALID-PARA
           ELSE
               DISPLAY "Given date is a valid date."
               PERFORM STOP-PARA.
           INVALID-PARA.
              DISPLAY "Given date is a invalid.".
              PERFORM STOP-PARA.
           STOP-PARA.
           STOP RUN.