I just got another VPS (first one's host decided to quit hosting) and the time the server shows (entering "date" via ssh) is exactly 24 hours in advance. The time is correct but it shows up one day forward.
It has cPanel/WHM and when I try to change the date it won't allow me. I've also tried via the date command in ssh but get an access restricted message (or something to that extent).
I assume your VPS provider is using either Virtuozzo or OpenVZ. This is one of the differences between those and Xen - with Xen, the system clock is virtualized as well, so you can control it via NTP from inside a virtual machine. Definitely a benefit if you have an application that requires accurate clock synchronization.
One comment on getting the host to run ntpdate - that only resets the clock at the current time. Over time, it will drift and become inaccurate again. It's best to have the host run NTP as a service on the main server node so that they time is regularly synced.