Don't quote me, but this year it opened around 4/14 or 4/15. I pulled the trigger with the DVC discount on 4/17 for myself and DW and barely made it. There were reported issues/access with some of the early registration options, but folks seemed to persevere. With the "specialty races" Donald and Goofy, races fill up quick and were sold out just as quick. There was a thread on the Wish forum which monitored the sellout rate. I'll see if I can find it and edit this post. Bottom line, it is very popular so you need to be in within a week of enrollment start. Hope that helps.