SAP ABAP Change date format

Data : w_date type dats value '20080903', 
          w_date1(10),
Constants : C(1) value '.'.
w_date1 = w_date.

concatenate w_date+6(2) w_date+4(2) w_date+0(4) into w_date1 separated by C.

Write : / w_date1.