Backup schedules

Ok, as far as I see, there is no option to schedule a backup with different settings on different days. Or do I miss something?

I would like to set up a schedule twice a week to backup all stuff on the server and another for every other day to just backup the databases.

I checked the backup.pl in the virutal-server directory, ... uhm, yes, ... where is the config? I would like to see, what this script does and look if I find a way around to setup my on script ;)

Any idea? :P