Apple's Kevin Lynch Explains Method Behind Apple Watch's Precise Timekeeping

42mm SS LB Apple WatchOne of the Apple Watch features Apple often highlights is the device's precise timekeeping, which Apple says is within 50 milliseconds of the global time standard. Apple's VP of Technology, Kevin Lynch, today spoke with Mashable and The Telegraph to share some details on how Apple achieves that level of accuracy.

Lynch told Mashable that the Apple Watch is so accurate that the hands of two Apple Watches placed next to one another will move in perfect unison. This is achieved primarily through 15 Network Time Protocol (NTP) servers that Apple has around the world, kept inside of buildings with GPS antennas that connect to GPS satellites broadcasting time data from the U.S. Naval Observatory in Washington, D.C. The Observatory houses an ultra accurate atomic clock, which uses electronic transition frequency to measure time.

Apple's time servers communicate the time to iPhones across the world, and the iPhone in turn syncs with the Apple Watch via Bluetooth to provide the exact time. Communicating a GPS signal from a server to an iPhone to an Apple Watch over Bluetooth has its own delays, which Apple corrects for via software. Apple's NTP servers make sure iPhones and Apple Watches keep time at "Stratum One" accuracy, within milliseconds of "Stratum Zero" devices.

Speaking to The Telegraph, Lynch also described the hardware inside of the Apple Watch that makes sure the time remains accurate. Each Apple Watch has a temperature-controlled crystal oscillator inside to combat time drift that clocks and watches see. The oscillator also makes sure the Apple Watch remains warm enough to keep accurate time in very cold climates. Thanks to this hardware, the Apple Watch is even more accurate than the iPhone.

"The second hand on every Apple Watch is perfectly in sync, and each device is accurate to 50 milliseconds of Co-ordinated Universal Time (UTC), the world's time standard, which is below human perception, so when you look at it you can't tell the difference," he explains.

With New Year's Eve approaching, Lynch says Apple Watch owners will have the most accurate watches in the room. "If you're in a room on New Year's Eve wearing one, you will be the best reference for when the New Year actually begins," he said.

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Top Rated Comments

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60 months ago
Apple's Kevin Lynch Explains Method Behind Apple Watch's Precise Timekeeping
hahahahahahahahaha it's a digital watch hahahahahahahaha

marketing at its best
Score: 35 Votes (Like | Disagree)
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60 months ago
It's so precise that their digital watch face does not even show seconds (and no way to turn it on)!!!!
Score: 34 Votes (Like | Disagree)
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60 months ago
I need my watch to (a) correct for relativistic effects of my movement, and (b) take into account the time it takes for the light to travel from the watch face to my eyes, adjust automatically based on the distance between the two, and the time it takes the signal to travel from my eyes to my brain. Time must not be just precise, it needs to be precise as to exactly when I perceive it. Also make it thinner.
Score: 25 Votes (Like | Disagree)
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60 months ago

Am I the only one that doesn't care about time accuracy that much?

I find it strange that a culture so obsessed with tracking the accurate time actually wastes so much of it.
Score: 23 Votes (Like | Disagree)
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60 months ago
Am I the only one that doesn't care about time accuracy that much? My non smart watch is about 1 minute out and I dont see why I need to change it - yes it be on time but 1 minute either side isn't going to make a difference - you dont tell people the time is exactly 3.03pm but you say 3.05 or 3.00 or just past...
Score: 23 Votes (Like | Disagree)
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60 months ago
I love my Apple Watch. Bring on version 2!
Score: 22 Votes (Like | Disagree)

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