take a look how the plsql TO_DATE function works... ie.. to_date(:P101_START_DATE,'mm-dd-yyyy')<=to_date(:P101_END_DATE,'mm-dd-yyyy'), etc..
i had tried this a few times but I kept getting an invalid numer to character error. Maybe my syntax was off. Let me try again.
I must have had syntax errors. I tried it again, the way you typed it out and it worked. Before I was using '/' instead of '-' to separate the date fields.