Syntax help for a BI Report

Summary

Need field to display 'All' when nothing is selected, but also need to format this field as a date.

Content

Hello all.  I'm looking for a bit of help with my syntax for a BI Publisher Report

I want to display the word "All" when nothing is selected, but I still need the field/object to be formatted correctly as a date on the output. I found a formula that does this, but I'm not having any luck developing the hybrid formula to do both.  So, how do I extend the All display rule to the date format formula I created? The field is called P_IN_DEL_DATE_FROM.