This freeware Atomic Clock Sync utility can help you keep your local computer up-to-date with the exact current time. This program will reference an atomic clock server to get the current time with the greatest accuracy available and update your PC's information. It can even be set to automatically check the time once a day to keep your PC's time accurate forever.
Atomic Clock Sync will connect to one of the time servers operated by the National Institute of Standards and Technology (NIST) in the United States, and will compare the time of your computer with the time on the servers operated by the NIST. This program will then display the difference between your system and the servers and if greater than 15 seconds, it will offer you the option of adjusting your PC by the displayed amount.
The overall uncertainty in this comparison should be no worse than +/- 5 seconds under all circumstances and will be substantially less than this value in most cases.
Version 2.7 removes the 'always on top' setting that caused problems for some users with a message box popping up behind the screen.
Version 126.96.36.199 addresses the start minimized problem with the 2.7 version.