While the official last date is December 2016, it is possible that the individual centers application procedures get over much before that. Most of the centers have a ceiling, and the applicants get those seats on the initiality, that means those who apply first will be eligible to get to sit at that particular centre.
CDS 2017 last dates
So, unless you are living near those centers that do not have a ceiling cap, it is advisable that you do not wait for the last date of registration and fee payment as you might not get the center of your choice.
The Last dates of registration and fee payment for having a chance to sit for the CDS I 2017 is __ December 2016. Post this there will be no application acceptance under any circumstances.
Make sure that all the information that you include in the form is true and authentic as if found untrue, you would be disqualified from obtaining the admission in the academy of your choice