I have this very simple formula in excel:
=DATE(YEAR($C$1),MONTH($C$1),15)+CHOOSE(WEEKDAY(DATE(YEAR($C$1),MONTH($C$1),15)),3,2,1,0,6,5,4) - 2
Cell C1 contains the current front month (Mar-07 as we speak)
It doesn't account for holidays on the specific Fri, but since it runs as a formula...