Basically: I wish Knott's passes were like Disneyland's. If I buy mine on November 25, 2013 - it expires November 25, 2014. I don't mind really, but now that I have a pass for Knott's (which I purchased in December) I am allowed one free visit this year, but the pass isn't "active" until 2014. If I want to visit the park and my one free visit is up, I have to pay $9.99 to get in until Jan 1, 2014 - and then pass is good all year.
I'm not complaining, it's just something I wish they did.