To change the timezone in OpenVZ, you will need to create a symbolic link from /usr/share/zoneinfo to the /etc/localtime file on your server.
First, you'll need to remove /etc/localtime:
rm -rf /etc/localtime
Now, all you need to do is create a symbolic link to your timezone replacing /etc/localtime. For example, if you live in Chicago you will need to run:
ln -s /usr/share/zoneinfo/America/Chicago /etc/localtime
Or, if you live in Amsterdam:
ln -s /usr/share/zoneinfo/Europe/Amsterdam /etc/localtime
After that, you should have your local timezone synced/set on your OpenVZ server.