One of the principle marketing lines during the initial marketing of the Apple Watch was that it was an extremely precise timepiece, and now Apple's Kevin Lynch has detailed why it's so accurate. Using synchronized Network Time Servers communicating with GPS satellites, Apple sends time information to iPhones around the world, which in turn send that information to the Apple Watch, which corrects for communication time delay. There's also specialized hardware inside the watch itself.
Apple also designed the Apple Watch to be an exquisitely accurate timepiece, building in what's known as a crystal temperature-control oscillator. Its job is to manage the vagaries of extreme temperatures, to compensate for drift and keep the Apple Watch time-accurate. Lynch actually told us that "as a piece of hardware, [Apple Watch is] far more accurate as a timekeeping device than the iPhone," said Lynch. It's actually four times better, he noted.
Lynch, Apple's VP of Technology and one of the heads of the Apple Watch project, also described how Apple tests the watch for accuracy. The company uses high-speed cameras to capture images of multiple watches at once, then watches frame-by-frame for any latency in the movements of the second hands.
You can read the full interview with Lynch at Mashable.