When I was in college, I bought and built a Heathkit GC-1000 WWV clock. Since then, I’ve been somewhat interested in accurate time measurement. I recently designed a GPS driven clock, but sometimes your local WiFi reception is better than GPS (say, indoors). For those circumstances, a clock that gets time from NTP over WiFi would be preferable. The newly released Raspberry Pi Zero W makes this quite a bit simpler to achieve