I have a WiFi project where I want to network a lot of ESP boards. I need time but it will not have Internet access. I want to have the normal working modules to be able to do regular NTP requests and get the time. So I want to have one dedicated ESP8266 that is the NTP server for the system.
I want to use GPS but might also consider a real time clock. That's just a detail. The part that I'm not familiar with is how to implement a NTP server.