Hi,
In case there isn!t NTP server you can set, you can go this way.
Procedure
In the vSphere Client inventory, select the host where the virtual machine is located.
Click the Configuration tab.
In the Software section, click Time Configuration.
Click Properties in the upper-right corner of the screen.
In the Time Configuration window, do one of the following:
To change the time manually, in the Date and Time field, set the appropriate date and time.
To synchronize the time kept by a host system to a reference NTP server, click Options and configure NTP server settings.
Click OK.
To set the Communication Manager virtual machine time, right-click the Communication Manager virtual machine and select Edit Settings.
In the Options tab, click VMware Tools.
Select the Synchronize guest time with host check box and click OK.
It's like 10secs googling mate
Regards.