went the day after my birthday to renew my cedula.
At the first office, they reviewed everything and sent me to the cash desk.
I paid, got my ticket and walked into the photo room.
The camera man explained to me that even though it had the expiry date as my birthday, because of limitations of their computer software, the real expiry date was the end of december, 6 months later. That meant it was two years to the day after it was previously renewed. He also told me that there wasn't anyway to renew before it had expired. He was kind enough to tape a small note with the date on to the barcode side of the cedula.
The girl at the cash desk returned my money without any problem.
I returned in january, no fine to pay, and the cedula was renewed, this time for four years (in line with renewed residency).