Why is my clock changing the time setting all by itself? on 2002 Volvo V70 XC

I can set the clock though it isn't always easy to do. Sometimes it does what it is supposed to when I turn the "stick" and other times it just takes off running forward at full speed no matter which direction I'm turning the control. When I do get it set it may only stay set for a couple of hours, sometimes longer, before it takes off and advances to another setting.

Asked by for the 2002 Volvo V70 XC