I now get in my logs (as shown by "systemctl status diffmon.timer" or journalctl): Nov 15 11:42:10 zira systemd[1]: diffmon.timer: Refusing to start, unit diffmon.service to trigger not loaded. Nov 15 11:42:10 zira systemd[1]: Failed to start Execute diffmon once a daily. Indeed, /lib/systemd/system/diffmon.service is missing.