The nice articles are available on HyperV time services as below
Time Synchronization in Hyper-V
http://blogs.msdn.com/b/virtual_pc_guy/archive/2010/11/19/time-synchronization-in-hyper-v.aspx
Time Synchronization and Domain Controller VM's
http://blogs.msdn.com/b/robertvi/archive/2011/05/11/time-synchronization-and-domain-controller-vm-s.aspx
MS Recommendation - Disable the time synchronization between the host system and guest operating system acting as a domain controller. This will enable VM - running as DC will get the Time from Domain.
Follow the steps To disable the Hyper-V time synchronization provider,
# Power-off the VM and
# Clear the Time synchronization check box under Integration Services.
http://technet.microsoft.com/en-us/library/virtual_active_directory_domain_controller_virtualization_hyperv(WS.10).aspx
MS Support Articles
How to configure an authoritative time server in Windows Server
http://support.microsoft.com/kb/816042
Hyper-V Time Synchronization Doesn't Correct the System Clock in the Virtual Machine if it is more than 5 Seconds ahead of the Host Clock
http://support.microsoft.com/kb/2618634
Other useful knowledge base
Windows Time Service Tools and Settings
http://technet.microsoft.com/en-us/library/cc773263(WS.10).aspx
