Yep. I just tried it again. For instance- the clock said 10:48 although it's almost 3 AM here and January 6, 2002. (Not too far off I guess ;-) I reset it to the proper time and date, cut it off, had a cigarette and cut it back on. The clock was already twenty minutes fast. Maybe the thing is doing some quantum computing on the side and has opened up a portal to a different space/time dimension :-)
Try this. Boot the machine to the BIOS. Set the clock in there, reboot and shut down before the OS comes into play. Go smoke a couple cigarettes, come back and reboot to the BIOS. Check the clock. If the time is off, then it's likely a dying battery on the motherboard.