What is wrong with my computer?

okay. so every single time i turn on my computer it will say that its like 2am and that it is november 30 2006. i change the time and date to the correct one everysingle time but it always goes to the november 2006 stuff. idk whats wrong but its getting really annoying and i always save my changes but it continues to revert back. please help me fix this thankyou