How will setup NTP Server settings on VMWARE ESX?

Configure ESXi/ESX to synchronize time with the Windows server Active Directory Domain Controller:

1. Connect to the ESXi/ESX host or vCenter Server using the vSphere Client.
2. Click the ESXi/ESX host in the inventory.
3. Click the Configuration tab.
4. Under the Software heading, click Time Configuration.
5. Click Properties.
6. Ensure that the NTP Client Enabled option is selected.
7. Click Options.
8. Click NTP Settings.
9. Click Add and specify the fully qualified domain name or IP address of the Windows server Domain Controller(s).
10. Click OK.
11. Click OK to save the changes.

Also note that you should be either having root or admin password or part of admin group to perform this task 

Do not forget to check in General tab that the service starts/stops with the host.