@Chris_Hafner - Thanks for coming back.. I think i got it sorted ... changed my tactic lol
Basically I was looking to create a extension attribute based on the time stamp of a plist and finding the days between the system date of a machine ..
Scenario - I deploy a policy that already creates a plist with a time stamp .. I then compare this time stamp with the system date and display this number as a EA .. then create a smart group based on this number that will then in fact deploy another policy .. Complex I know but.. I have it working 🙂