Hi:
Ken is right - rdate is the way to go.
Way back in '95, I wrote an article for Sys Admin - A server based Date/Time Synchronizer for TCP/IP. The program is a "C" utility using the port 13 daytime service - very basic.
If you can't find anything else, post an email address and I'll send you a copy of the article and the source.
Regards,
Ed