In System Admin \ Time Zone you can specify the timezone area and the city.
It would be great if you could also specify the NTP server as well.
We have a local NTP server. How can you configure FreePBX to use a local NTP server ?
Don’t configure FreePBX to do it - let Linux handle it. Just set the system (Linux level) to use your NTP server and call it good.
I’m not a Linux expert.
How do you set the system (Linux level) ?
Set up NTP service on CentOS/RedHat
That’s a reasonable start. The only way it could be simpler would be if it did it itself.