Create option for scheduling regular Git GC's

Related to https://answers.atlassian.com/questions/12270327 .
It would be great to have an option to schedule regular, pre-emptive Git GC's. (e.g. run GC every day at 2:00AM or every week on Sunday at 5:00AM)

Git GC is quite resource-intensive on big repos and the response time towards users degrades while it is running.
I would like Stash to run pre-emptive GC's at times of low load, to avoid them being triggered automatically by Git after a push in the middle of the workday.