Hello,
You can simply use kron job to automate this. Pleas see below link:
https://supportforums.cisco.com/discussion/11531891/automatic-config-backups-routers-catalyst-switches-and-asa
kron occurrence monthly at 01:23 june 20 recurring
policy-list save-config
!
kron policy-list save-config
cli copy system:/running-config tftp://192.168.1.2/router-confg.txt
HTH
G1