how to create daily task for GMVault in automator
As you mentioned you can use cron which is more transferable knowledge since it's used also on other platforms. Or you can use LaunchDaemon which is more Macish ;)

Cron

Please refer to question How do I run a cron job on a Mac?

Launchd


Doc
short how to


file for service looks like this
you will copy that file into /Library/LaunchAgents. If you want the daemon to be launched when you login, not when your computer start, just prepend ~(home) before the path



I am sorry for linking the code instead paste it here, but it seems i am not compatible with code adding here on apple.stack ;)