Your OpenVZ will reflect the host server's time settings by default; however, it is possible to configure your VPS to use a custom timezone, such as the one you (or your users) reside in.
To set your server's timezone, first log in as the root user via SSH, then run the following command to list all available timezones:
# find /usr/share/zoneinfo/
You can use grep to refine the search:
# find /usr/share/zoneinfo/ | grep -i turkey
Once you have selected a timezone, create a symbolic link to /etc/localtime:
# ln -f -s /usr/share/zoneinfo/CST6CDT /etc/localtime
To verify the timezone change, use date: