Okay, I went onto the WDW website and printed out a form for the DDE. It is a membership application for Annual Passholders.
On the form it says, once they receive it, the card will be mailed within a three to six week period. The card is valid from the day Disney mails it out to you. Does that mean that you loose about four weeks on that card? Doesn't make sense.

I am going April 16th, should I apply by March 16th? Not too sure.