I did it by
DECLARE
V_HD EMP.HIREDATE%TYPE;
V_FM VARCHAR2(30);
V_STAR VARCHAR2(30);
BEGIN
V_FM :='&FORMAT_MASK';
V_HD:=TO_DATE('&HIREDATE',V_FM);
DBMS_OUTPUT.PUT_LINE(V_HD||CHR(10)||TO_CHAR(V_HD,V_FM));
V_STAR:= CASE WHEN V_HD BETWEEN TO_DATE('01-01'||'-'||to_char(V_HD,'yyyy'),'dd-mm-yyyy') AND TO_DATE('01-02'||'-'||to_char(V_HD,'yyyy'),'dd-mm-yyyy')
THEN 'YOUR STAR is capricorn'
ELSE 'any other star'
END;
DBMS_OUTPUT.PUT_LINE(V_STAR);
END;