Since we have a lot of people from all around the world almost anyone will need to have his VPS time changed.
You will not be able to change the VPS date, only the timezone can be changed.
In order to change the timezone on your VPS you will need to access the Machine settings -> Set timezone option and select the timezone appropiated to your localtime.
If you want to manually change the timezone you can also do that following the OpenVZ wiki page here:
http://wiki.openvz.org/Timezone
