Automatic nightly CWM nandroid backup?

I am using Cyanogenmod with CWM and am currently doing a manual weekly Nandroid backup (plus daily scheduled TitaniumBackup runs). Needless to say, it is easy to skip or forget. Is there a way to have the nandroid backups automated? I.e., I would like the phone to shutdown into recovery once a week, do a backup, and reboot.