Appears that your internal PRAM memory battery has died & needs replacement. What model PowerBook do you have?
Here's something to try. Startup in Safe Mode (depress the Shift key at startup). The startup may take a while while some "ficxes" are being made. After you are booted, open the Date & Time preference window. If you are connected to the internet, be sure to check Set date & time automatically. Now the time should be correct. Then you can restart normally.
How are you connecting to the Internet? Normally, the system will look for time from a time server like time.apple.com at boot and you wouldn't see a message like you are getting. However, if, as noted above, the backup PRAM battery has died (not unusual at all for a PowerBook at this point in time) and you are not connected to the internet at boot, then the default Mac OX X time will be set, which is as I recall midnight, January 1, 1970 GMT.
If you are not connected to the internet when bringing up Date & Time in System Preferences, and the "Set Date & Time Automatically" box has been checked, then the Date & Time preference will hang trying to set the time.
So, there are two answers to your issue here. In no particular order of importance, they are:
- Make sure you are connected to the internet at boot (not always possible with some TiBooks when using AirPort) or when bringing up Date & Time preferences; or
- Replace the PRAM backup battery (some PowerBooks do not have same).
I am trying to find the preference file that contains the set time automatically flag and have been so far unsuccessful. If found, you could possibly trash it or move it to the desktop to at least access Date and Time.