^[1|2]\d{3}/(0?[1-9]|(1[0-3]))/((1\d)|(2\d)|(3[0,1])|(0?[1-9]))$
^\d{2}\/([1-9]|(1[0-2]))\/((3[0,1])|([1,2][0-9])|([1-9]))$
^\d{2}\/((0?[0-9])|(1[0-2]))\/((3[0,1])|([1,2][0-9])|(0?[1-9]))$
^\d{2}\/((0?[1-9])|(1[0-2]))\/((3[0,1])|([1,2][0-9])|(0?[1-9]))$