I was trying the TO_DATE function. Specifically, I noted that the following queries
TO_DATE
1. SELECT TO_CHAR(TO_DATE(\'01-01-2015\',\'DD-MM-YYYY\'),\'DD-MO
The output format of TO_CHAR is not correct, try:
SELECT TO_CHAR(TO_DATE('01-01-2015','DD-MM-YYYY'),'DD-MM-YYYY') FROM DUAL;