Looks like 'EEE' is not a supported AwareIM date format yet.
I added a 'DateString' Attribute and used this rule to convert the date and get the format I needed.
BOname.DateString=CHARS_FROM_LEFT(DAY_OF_WEEK(BOname.Date),3)+' '+AS_STRING(BOname.Date,'MM/dd/yyyy')
AwareIM support, it would be nice to have this date format like we do with 'DAY_OF WEEK' function so we don't have to convert it all the time.