Using a local Network Time server (NTP)

Ardexa Linux uses systemctl-timesyncd for clock synchronisation. This will be autmatically done. For troubleshooting, or to configure one or more local, custom NTP servers, first scan the local network for port 123/udp
# scan the local network for open NTP ports, your IP subnet will
# most likely be different. Routers are most likely to have the port
# open and active
nmap -sU -p 123
# check the port is actually responding to requests
nmap -sU -p 123 --script ntp-info
Next, edit the file /etc/systemd/timesyncd.conf and add the IP to the file (the use of FallbackNTP is taken from here, e.g.
printf '[Time]\nNTP=\nFallbackNTP=' > /etc/systemd/timesyncd.conf
Finally, restart the service to activate the new NTP servers and then check the status. If the timezone is changed on the edge device, make sure to call "Refresh metadata" on the device.
# restart the service to re-read the config
systemctl restart systemd-timesyncd
# The following commands will probe the status of the service
systemctl status systemd-timesyncd
timedatectl timesync-status
timedatectl show-timesync