Windows has a built-in “service” that allows your computer to reference an atomic clock server, such as the atomic clock servers operated by the National Institute of Standards and Technology (NIST) in the United States. Your current computer time is compared with the current atomic time and an adjustment is made to keep your local computer up-to-date with the exact time now.
In order to keep your computer time synchronized with a server to which our station is synchronized, please use time.nist.gov server. More information and a list of official time servers is available here > http://tf.nist.gov/tf-cgi/servers.cgi
Atomic Clock Sync
While it is great to have this functionality in Windows, configuring this time service is painful! If you want to sync more often than the default, you have to be very comfortable editing the System Registry OR you can use Atomic Clock Sync program to do the work for you. This program can be downloaded free of charge, here > Atomic Clock Sync.
Atomic Clock Sync version 3.5 requires Windows 8, Windows 7, Vista, Windows Server 2003, Windows XP, or Windows 2000. Version 3.5 is now compatible with both 64-bit and 32-bit Windows! It is an executable file that does not require installation. Just run it whenever you want to review and/-or reconfigure your Atomic Clock Sync settings in Windows or when you need to repair the Windows Time Service in Windows.
IMPORTANT NOTE: You must have the correct time zone selected on your computer AND have the correct daylight saving time rules in place in your operating system in order to have the Internet Time synchronize process work properly. If the dates for Daylight Saving Time (DST) changed recently in your area, you must update your operating system with the new rules. Microsoft releases patches when necessary for newer versions of Windows, but with older versions, you may have to update the registry yourself or find a third-party tool to do it.