Carla, don't worry about the date on the card, just send it in if you want the video. All you really need is to have DCL (or your TA if you used one) have the code applied to your reservation and if you qualify (have no other shipboard credits and your sailing is not blacked out for credits) then you'll get the credit.
GET UP TO A $1000 SHIPBOARD CREDIT AND AN EXCLUSIVE GIFT!
If you make your Disney Cruise Line reservation with Dreams Unlimited Travel you’ll receive these incredible shipboard credits to spend on your cruise!