Setting Up The NTP Servers
To set up the NTP servers:
Launch a browser window, and enter the Administration Portal URL displayed in the vSphere vCenter Console tab for the virtual machine you want to configure or use the link from page. The URL uses the following format and is case sensitive:
https://<ApplianceIPAddress>
In the left pane, click APPLIANCE MANAGEMENT.
Click Edit for NTP.
Select the Enabled check box. Enter the host name or IP address for a Preferred and Secondary NTP Server and click Apply.
To exit, click Cancel.