Sorry if this is a dumb question, but do you guys not have radio controlled clocks outside of Europe?
If I got it right, the only purpose of this project is to always display the correct time. Radio controlled clocks do exactly that. They are cheaper than the one ESP board, and run years on a single AA battery. No WiFi, tinkering, setup, or cables necessary
The point is to have fun and learn something, not really to solve a problem in a practical sense. The radio controlled clocks are extremely unreliable where I live.
Our office manager bought some US tuned radio wall clocks, and every now and then they would jump 8 hours forward. I assume it was down to solar weather making propagation changes (https://en.wikipedia.org/wiki/Sporadic_E_propagation)
An already radio controlled clock would probably be a better starting point to GPSify or NTPify too - at least the one I have already has the feature that it can move the hands to an arbitrary position (when you replace the battery and it syncs again).
We do, but I've never had a WWVB clock work for me in North Carolina. I've tried a few of them. The US is a big place and for whatever reason, there aren't that many clock signal transmission towers (AFAIK, the only one in the US is in Colorado).