net time \\<computername> /querysntp

To query where it’s getting it’s time from.  Can compare to a working machine if possible.

If all looks fine, check Windows Time service.  My case, this was disabled which meant the time kept jumping 2hrs ahead every few mins (if I set it back).

w32tm /query /status

On a Windows 2008 R2 and newer server

http://newforma.custhelp.com/app/answers/detail/a_id/453/~/how-to-tell-from-what-server-a-computer-is-getting-its-time

Or in the registry
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\NtpServer

Also could be related to vsphere overriding the Windows time.