CREATE OR REPLACE PACKAGE n_to_nth
IS
   FUNCTION n_to_nth (n_in IN NUMBER)
      RETURN VARCHAR2;

   /* Alias for n_to_nth */
   FUNCTION nth_from_n (n_in IN NUMBER)
      RETURN VARCHAR2;

   /* Convert day of month to word */
   FUNCTION dd_to_nth (dd_in IN NUMBER)
      RETURN VARCHAR2;

END;

CREATE OR REPLACE PACKAGE BODY n_to_nth
IS
   /* Utilize date functions to conver "1" to "1st" and first" etc. */

   FUNCTION n_to_nth (n_in IN NUMBER)
      RETURN VARCHAR2
   IS
   BEGIN
      RETURN CASE
                WHEN n_in IS NULL
                THEN
                   NULL
                WHEN n_in = 0
                THEN
                   NULL
                ELSE
                   LOWER (
                      TO_CHAR (TO_DATE ('1-1-' || n_in, 'dd-mm-yyyy'),
                               'FMYYYYth'))
             END;
   END;

   FUNCTION nth_from_n (n_in IN NUMBER)
      RETURN VARCHAR2
   IS
   BEGIN
      RETURN n_to_nth (n_in);
   END;
   
   FUNCTION dd_to_nth (dd_in IN NUMBER)
      RETURN VARCHAR2
   IS
   BEGIN
      RETURN CASE
                WHEN dd_in IS NULL
                THEN
                   NULL
                ELSE
                   LOWER (
                      TO_CHAR (
                         TO_DATE ('2010-01-' || LPAD (dd_in, 2, '0'),
                                  'YYYY-MM-DD'),
                         'DDSPth'))
             END;
   END;
END;

BEGIN
   DBMS_OUTPUT.put_line (n_to_nth.n_to_nth (1));
   DBMS_OUTPUT.put_line (n_to_nth.n_to_nth (3));
   DBMS_OUTPUT.put_line (n_to_nth.n_to_nth (100));
   DBMS_OUTPUT.put_line (n_to_nth.dd_to_nth (1));
   DBMS_OUTPUT.put_line (n_to_nth.dd_to_nth (3));
   DBMS_OUTPUT.put_line (n_to_nth.dd_to_nth (27));
   DBMS_OUTPUT.put_line (INITCAP (n_to_nth.dd_to_nth (27)));
END;