…that the system is rebooted as often as really necessary but not more than that, in order to maximize uptime, and not annoy the user needlessly. After all, rebooting means disruption, and unavailability of the system's services.
With systemd v257 the systemd-logind service gained a new centralized knob for designating a specific "maintenance time" for systems via the new DesignatedMaintenanceTime= setting in logind.conf.
It takes a calendar time expression (in the same format…