Windows Time Group Policy Settings

Policy location

Computer Configuration
  Administrative Templates
    System
      Windows Time Service

The main folders are:

Global Configuration Settings
Time Providers

Common policies

Policy	Purpose
Global Configuration Settings	Controls service-wide values such as correction limits, update intervals and clock discipline.
Configure Windows NTP Client	Configures the peer list, synchronisation type, cross-site behaviour and polling values.
Enable Windows NTP Client	Enables or disables the Windows NTP client provider.
Enable Windows NTP Server	Enables or disables the Windows NTP server provider.

Typical use

A policy for the forest root PDC Emulator may configure:

Type = NTP
The approved manual peer list.
The required NTP client settings.

Other domain controllers and domain members should normally continue using the Active Directory hierarchy.

Do not apply one policy to every domain controller

Linking a manual external peer policy to the entire Domain Controllers OU configures every DC as though it were the top of the hierarchy.

Scope the policy so that it follows the current forest root PDC Emulator role holder, or manage the role change as part of the documented FSMO transfer procedure.

Verify the applied result

gpresult /h C:\Temp\gpresult.html
w32tm /query /configuration
w32tm /query /source
w32tm /query /status

The effective configuration output identifies many values supplied by policy. Always verify that the selected source also changed as intended.