The recording of time started with observing the movement of celestial bodies and numbering the hours of the day. As technology increased, humans became more and more interested in accuracy when it came to telling time. Now, we have atomic clocks (the development of which led to much better wristwatches) that use a microwave signal emitted from atoms as they change energy levels. To synchronize your watch for the most accurate time possible, you will first have to know how to set your watch's time and then check a universal/atomic clock to match your wristwatch's time to it. The process is simpler than it sounds.
Prepare your watch for setting. An analog wristwatch will probably have a button on the side that needs to be pulled into the second of three positions, especially if it's a chronometer watch. A digital watch will have a button on the side that will need to be pushed in to set the watch's time.
Set the hour and minute of your watch to the current hour and minute. Allow the watch to run until the second hand, or the seconds, is at zero. If this changes the minute over, that's okay. You'll change it again when you compare it to the atomic clock. Pull out or push your button again to stop your wristwatch from running and prepare it for setting.
Visit www.time.gov. This is the official time according to the U.S. Government. Choose your timezone, according to the map. Wait for the time to load.
With your hand poised over the minute button/hand on your watch, wait until the current minute changes over and the seconds are at zero on the atomic clock. When the seconds are at zero, change your minute to the next one. For example, if it is 1:12 p.m., wait until the atomic clock says 1:12:59. When it changes to 1:13:00, change your watch to read 1:13. Your watch will be synchronized.
You can use the same method to synchronize your watch to any other timepiece, whether it is atomic or not. People often synchronize their watches according to standard time so that they are on the same time, even if it is very slightly inaccurate.