Often our server and workstation doesn’t have the right time. Best way is to change the NTP time server on the Domain Controller. Here’s how to change your time server from what ever it is now to another NTP server.

 

Below steps must be perform on the domain controller.

  1. Open the command prompt and type: net stop w32time
  2. Configure the external time sources, type: w32tm /config /syncfromflags:manual /manualpeerlist:0.pool.ntp.org
  3. Make your PDC a reliable time source for the clients. Type: w32tm /config /reliable:yes
  4. Start the w32time service: net start w32time
  5. The windows time service should begin synchronizing the time. You can check the external NTP servers in the time configuration by typing: w32tm /query /configuration
  6. Check the Event Viewer for any errors.

 

Another good source and more details  can be found here:
http://www.thirdtier.net/2011/02/how-to-set-an-ntp-time-server-in-windows-2008-sbs-2008-and-sbs-2011/