It seems the date command has documentation spread all over the internet and it can sometimes be a pain to sift through it.. so here you go. the easiest way to change the date and timezone is as follows..
[bash][root@host ~]# date –set 11:31
[root@host ~]# cp /etc/localtime /etc/localtime.bak
[root@host ~]# rm -f /etc/localtime
[root@host ~]# ln -s /usr/share/zoneinfo/America/Chicago /etc/localtime
[root@host ~]# date
Mon Mar 23 11:33:33 CDT 2009
This is a very basic example, and in most cases its best to sync to an NTP server, but this will help provide a base understanding.