I had to migrate a couple of cron jobs over to systemd timers. This is a short walk through on how I did it for my DuckDNS updater. Basically, we need to create two files under /etc/systemd/system or /etc/systemd/user dep. on your specific needs. For DuckDNS I created the config under /etc/systemd/system. So any filenames or paths that are not rooted paths are in relation to /etc/systemd/system, so adjust accordingly for your own needs.