Look for any "ntp" messages in your /var/log/messages file:
grep ntp /var/log/messages | tail
And make sure ntpd is running:
ps auxwww | grep ntp
[edit]And it will not make large changes in time immediately. It changes your clock gradually so as not to cause time sensitive apps to freak out..[/edit]
[ August 19, 2002: Message edited by: VoidMain ]