There's three things to check.
1. The timezone setting for the server. The is /etc/localtime. If you look in the /usr/share/zoneinfo/ directory structure you'll find the appropriate timezone that you wish to use. Then issue these commands (I'll use US Central Time in the example):
CODE
mv /etc/locatime /etc/localtimeOLD
ln -s /usr/share/zoneinfo/US/Central /etc/localtime
2. The system date for the server. You already know how to do this one. Do a 'date' command to grab what it thinks the time is after you set your TZ correctly, then set it with 'date -s'
3. The hardware date for the server. Sync the hardware clock to what the OS says the time is:
CODE
hwclock --systohc
That should do it!
One note: If this is a VPS all you can do is change the timezone.