You can sync your windows guest vms within vmware tools, there is a tick box to sync it with the host.
Or if they are on a domain, use the DC to control time, or if not on domain, then you could manually enter an external time source.
Within the vi client check the date and time and see if it is out, if it is, check the time source it is using and enter an external source.
Hopefully this will help you,
Dan
