Smart & Connected Life Smart Watches & Wearables Why the Apple Watch Is the Most Accurate Timepiece out There Learn how the timepiece maintains optimal performance Share Pin Email Print bombuscreative / Getty Images Smart Watches & Wearables Headphones & Ear Buds Smart Home Smart Watches & Wearables Travel Tech Connected Car Tech iPods & MP3 Players By Emily Price Writer Emily Price is a former freelance contributor to Lifewire and a freelance tech writer who focuses on emerging technology. our editorial process Emily Price Updated February 14, 2020 Not only is the Apple Watch the best selling watch in the world, but it is also the most accurate. When it comes to the Apple Watch, accuracy is exceptionally important. Several things go on behind the scenes to ensure that the watch is always as accurate as possible. Here's how the timepiece maintains optimal performance, no matter where your travels take you. Why the Apple Watch Is the Most Accurate Timepiece It isn't easy to be the most accurate watch in the world. Here are a few reasons Apple delivers the most accurate watch on the market. To support the Watch, Apple built a Network Time Protocol (NTP) that operates using servers located in different locations. Those servers ensure that the time that appears on the Apple Watch is as close to Stratum 1 accuracy as possible.The second hand on the watch is perfectly in sync with the second hand on every other Apple Watch. Each device is accurate down to 50 milliseconds of Coordinated Universal Time (UTC). While one Apple Watch may be a tiny amount off from another, they're so close that no human can perceive the difference.The time on the Watch comes from atomic clocks, which measure time using the resonant frequency of a cesium atom—an atomic element—which works out the seconds. The time is served to GPS satellites that orbit the Earth, where high-precision time is used to determine location. That time is broadcast to servers deployed around the world to receive the signals from GPS satellites and share the time with a time server, which in turn communicates with the watches.Apple tested the Apple Watch in a variety of weather conditions to ensure its accuracy everywhere. The watch adjusts in cold weather, a situation where watches are often less accurate, to ensure it maintains a consistent time.The Apple Watch team used high-speed cameras to test the accuracy of the Apple Watch. The team filmed the screen at 1,000 frames per second, ensuring that each watch has millisecond precision. That precise time comes from an atomic clock within the Apple testing lab. Exceptional Accuracy All that together makes for one exceptionally accurate timepiece. Next time you try to decide which of your friends has the most accurate cellphone or watch time, throw out a few of these facts about your Apple Watch, you're likely to win the argument every time.