In RHL (at least as long as I've been running it, starting with
4.2) there are two root-runnable utilities that help out with that. The
first is timeconfig (in /usr/sbin), which is used for Time Zone concerns;
it's one of the character-mode administration tools you can invoke with
/usr/sbin/setup. The other is timetool (in /usr/bin), which you can then
use to set the time; it's one of the X11 administration tools you can
invoke with /usr/bin/control-panel.
Matt