Time/Date reverting to factory setting

[mad.catlady]

Hi there, can anyone help me?!!
My time / date reverts to what i presume is a factory setting, not all the time, but maybe once every week or fortnight. I then change it back and padLock it, only for it to change again in a wee while. So frustrating. Any ideas?
I have a macbook OSX version 10.6.8

 

[charlieegan3]

are you ever holding down the power button to force computer off?

Battery ever run out of charge?