https://wiki.archlinux.org/index.php/Systemd/Timers
\cat /etc/systemd/system/certbot.service [Unit] Description=Renewal certificates [Service] Type=oneshot ExecStart=/usr/bin/certbot renew
\cat /etc/systemd/system/certbot.unit [Unit] Description=Automatic renewal certificates [Timer] OnCalendar=daily 00:00:00 Persistent=true [Install] WantedBy=timers.target
sudo systemctl enable certbot.timer