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.
UPDATE: It seems that as of 16.04.1 this is not an issue for me any more. There have been plenty of reports regarding WiFi issues on Ubuntu 16.04. The majority of issues seems to stem from suspend/resume issues where the network would not re-connect, show the wrong icon in the top bar or similar. The temporary workaround for this is to restart the network manager if you have no network at all, or, if you have network but the nm applet is showing the wrong status, just restart the nm applet.