When I've had problems with incorrect time is when I install another linux distro and suddenly my other distro's clock will show back or forward 4 hours. I then have to reset my BIOS clock and all is well.
You are doing it correctly, if it asks for your admin password when you hit 'apply' in the time/date GUI and then ok. Wait one minute and the correct time will show in your toolbar clock. I just tried mine out. If I set the clock ahead an hour, it will also set my BIOS clock ahead an hour. If I reset my BIOS clock to back to correct hour, it automatically resets Pardus os clock correctly.
Here are some command lines. but it has been a while since I've used them as I remember having problems understanding the difference between hardware clock and system time:
there's also man pages for both, more detail information.
The following will show current date and time, as well as timezone:
sudo hwclock -r