Add n number of working days to date

Simply add the below FORM into you ABAP code and call it using the usual PERFORM command:
   DATA: ld_date TYPE sy-datum.
 PERFORM calculate_date  using '-4'
    changing ld_date.

*&---------------------------------------------------------------------* *& Form CALCULATE_DATE *&---------------------------------------------------------------------* * Add/Subtract n number of months from a date *----------------------------------------------------------------------* * --> p_months Number of months to add/subtract * <-- p_date Start date and result date *----------------------------------------------------------------------* FORM calculate_date USING p_months CHANGING p_date. DATA: ld_datestor TYPE sy-datum. ld_datestor = p_date. CALL FUNCTION 'MONTH_PLUS_DETERMINE' EXPORTING MONTHS = p_months OLDDATE = p_date IMPORTING NEWDATE = p_date. ENDFORM. " CALCULATE_DATE