Quote Originally Posted by javamaid
The function accepts only dd-mon-yy format....
What it accepts is a date data type. If you supply a character string then Oracle will attempt an implicit conversion using the session's value of nls_date_format. The problem with this is that it can be changed system-wide or by the client, so the best practice (indeed the only acceptable practice) is to always use an explicit conversion.

If you are going to insist on two-character years then use the RR format to convert, and consult the docs to understand what it and other format elements mean http://download-west.oracle.com/docs....htm#sthref429