Remove Old Meeting Messages calendar attendant

There are questions regarding when meetings that haven;t been accepted or declined(maarked as tentative in calendar) are removed from the users calendar.  We are using default exchange 2010 settings.  Enable calendar attendant, remove old  meeting messages.

When will tyhe "old" meeting requests be removed?  Is it when the attendant processes and how would I know when that processes if this is the case or is it some other reason?

Thanks.