We normally run automated backups once weekly but while writing testing instructions for bug
MDL-33812 I decided to change this to every day (since this would mean new and/or changed behaviour would be much more immediately apparent). However, after two days, I'm sorry to say that no additional automated backups have been performed which means this is yet another backup setting not being honoured.
I have now filed bug reports for the main three backup settings; backup_auto_storage, backup_auto_keep and now this one. We have backup_auto_storage set to 1 ('Specified directory for automated backups') and I strongly suspect this setting is behind all the broken behaviour that I'm observing but this is a setting I'm not prepared to change since the contents of this directory are regularly rsynced to a second (remote) storage location for double-safe keeping.