Recently I found that on my VPS server there is incorrect time often called time drift. As you know having correct time is very important - especially in Active Directory environments. Back to my case - I have VPS running on XEN and I reported to hosting company this issue. They replied that they will not change ntp settings for hosts but they said that I can do it by myself.
So encouraged by them (of course by not solving my ticket at all) I did small digging and I found this solution.
echo "1" < /proc/sys/xen/independent_wallclock
I just restarted ntpd deamon and now I am synced quite ok. I assume you configured your box as ntp client - which is of course so trivial that I will not describe it.
[root@vps]# **ntpq -p** # remote refid st t when poll reach delay offset jitter +nac.oa.uj.edu.p 126.96.36.199 2 u 24 64 377 17.076 -12.822 14.582 *ntp.ifj.edu.pl 10.0.2.4 2 u 24 64 377 18.393 -20.868 6.604 histeria.pl .INIT. 16 u - 64 0 0.000 0.000 0.000 LOCAL(0) .LOCL. 10 l 28 64 377 0.000 0.000 0.001