Linux - Change timezone

[root@s5 etc]# cp /etc/localtime /etc/localtime.bkup
[root@s5 etc]# cp /usr/share/zoneinfo/US/Eastern localtime
cp: overwrite `localtime'? y
[root@s5 etc]# date
Sat Oct 15 21:38:52 EDT 2005

Just to be sure it's correct
[root@s5 etc]# rdate -s rdate.darkorb.net