systemd-shutdownd.service, systemd-shutdownd.socket, systemd-shutdownd — Scheduled shutdown service
systemd-shutdownd.service
systemd-shutdownd.socket
/usr/lib/systemd/systemd-shutdownd
systemd-shutdownd.service is a
                system service that implements scheduled shutdowns, as
                exposed by
                shutdown(8).
                systemd-shutdownd.service is automatically activated on request and terminates
                itself when it is unused.