Two things and some links for you. First of all, the Global Catalog server needs an external time server to synchronize with, second of all W32time automatically synchs the time with the Global Catalog server. If you would like a simple way to just keep time within the network the same, then check out the NET TIME command from the CMD prompt. It can be integrated into batch files, or other scripts.

http://search.microsoft.com/default....us/itresources

That is a search of technet on the W32time service, some of the articles might be helpful...in particular, this one:
http://www.microsoft.com/technet/tre...te/wintime.asp

Regards,
Wizeman