Time keeping in a virtual environment can be a challenge to setup.

To help you, VMware has maintained a KB on the subject.
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1318

The KB presents best practices for achieving accurate timekeeping in Windows Guest operating systems. These recommendations include a suggested configuration for timesynchronization in the guest and on the host.

A more specific guide also exists for Windows and Linux servers:
For Windows read:
http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&externalId=1318&sliceId=1&docTypeID=DT_KB_1_1&dialogID=73678717&stateId=0%200%2078515868
For Linux read:
http://kb.vmware.com/selfservice/microsites/microsite.do?cmd=displayKCPopup&docType=kc&externalId=1006427&sliceId=1&docTypeID=DT_KB_1_1

It’s great reading, but very nerdy 🙂