The watches/clocks they are talking about listened to WWV, a set of radio stations transmitting from Fort Collins, Colorado. The system long predates the Network Time Protocol you're referring to. Radio controlled clocks/watches had no means for accounting for latency.

[–] Unforeseen@sh.itjust.works 1 points 3 months ago (1 children)

Ahh OK my bad. I've only worked with NTP for a long time and wasn't aware of the earlier stuff.

[–] Rivalarrival@lemmy.today 1 points 3 months ago

If you're interested in prehistory, listen to this for a couple minutes.