Automatically Deleting Based on Date

I'm using the following recipe to save messages to a unique folder based
on their dates.

        :0:
        * $ ^From: majordomo$PGHOST
        * ^Subject: (Majordomo results:) .* (who)
        PG/Backup-`date +%m-%d`

I haven't figured out how to have it delete the previous folder
automatically. These messages are received (if everything works out) once
a day. Thus, the previous folder is the day before. 

If you can figure out how to have it check to see if the previous folder
exists and how to delete it, I'd appreciate it.

Thanks,

 ------------------------------------------------------------------------- 
 | Brock Rozen | brozen(_at_)netvoyage(_dot_)net | 
http://www.netvoyage.net/~brozen | 
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