I think you are on target Rover. I think the Date is 1 Jan 2011. But with VA they could say from the date that you had the C&P exam.
That's what happen to me.
Reason for: is even though you filed the claim in Dec 2011. the Va can say that the condition did not worsen until the exam and date it the day of the exam. So, if the effective date is 2013, that is probably what the did.
Reddit
Today, I received VA brown envelope -- the effective date is Jan 1 2011 @100% so i'm speechless.
Thank God for Hadit Forum!!! I've spent countless hours reading members and moderators posting. I would not have been successful without this Forum and Members encouragements and recommendations.