SQL>
SQL> create or replace function f_isSunday (in_dt DATE)
2 return VARCHAR2
3 is
4 v_out VARCHAR2(10);
5 begin
6 if to_char(in_dt,'d')=1 then
7 v_out:='Y';
8 DBMS_OUTPUT.put_line('IsSunday=Y');
9 end if;
10 return v_out;
11 end;
12 /
Function created.
SQL>