NBU Policy Scheduleing help

Im using NBU 7.5 on Oracle Solaris 10

I want to be able to have my Full level backup policies that I perform once a month run on the last day of the month or last friday of the month...  How do I set it up to run like this in regard to the policy schedule...  Do I have to exclude every day in the month so it run on that last day available?? 

thanks