CREATE OR REPLACE FUNCTION is_weekday (date_in               IN DATE) 
   RETURN BOOLEAN 
IS 
BEGIN 
   RETURN TO_CHAR (date_in, 'D') BETWEEN 2 AND 6; 
END; 

DECLARE 
   l_date   DATE := DATE '2018-09-10'; 
BEGIN 
   DBMS_OUTPUT.put_line ('If your weekend is Saturday and Sunday....'); 
 
   FOR indx IN 1 .. 7 
   LOOP 
      DBMS_OUTPUT.put_line ( 
            TO_CHAR (l_date, 'FMDay, Month DD YYYY') 
         || ' is ' 
         || CASE WHEN NOT is_weekday (l_date) THEN 'not ' END 
         || 'a weekday'); 
      l_date := l_date + 1; 
   END LOOP; 
END; 

CREATE OR REPLACE FUNCTION is_weekday (date_in               IN DATE) 
   RETURN BOOLEAN 
IS 
BEGIN 
   RETURN TO_CHAR (date_in, 'D') BETWEEN 2 AND 6; 
END; 

DECLARE 
   l_date   DATE := DATE '2018-09-10'; 
BEGIN 
   DBMS_OUTPUT.put_line ('If your weekend is Saturday and Sunday....'); 
 
   FOR indx IN 1 .. 7 
   LOOP 
      DBMS_OUTPUT.put_line ( 
            TO_CHAR (l_date, 'FMDay, Month DD YYYY') 
         || ' is ' 
         || CASE WHEN NOT is_weekday (l_date) THEN 'not ' END 
         || 'a weekday'); 
      l_date := l_date + 1; 
   END LOOP; 
END;