Using systemd timers for Let's Encrypt renewal on Nginx

Both files needs to be added to:

/etc/systemd/system/

To start the timer:

$ sudo systemctl start certbot-renew.timer

To enable the timer to be started on boot-up:

$ sudo systemctl enable certbot-renew.timer

To show status information for the timer:

$ systemctl status certbot-renew.timer

To show journal entries for the timer:

$ journalctl -u certbot-renew.service

Credit: https://stevenwestmoreland.com/2017/11/renewing-certbot-certificates-using-a-systemd-timer.html.