I did go there first but it won't let me use a publication date past this Friday. Looks like they're cutting people off... I was hoping to get it in and order a proof copy asap. I've read that KDP will offer this also so let's see as soon as I've finished the uploading process.
Createspace isn't cutting anybody off. The field where you set the publication date is for dates in the past (i.e., for a book that has been previously published). For a new book, leave it blank. The publication date will be the date you approve the proof. There has never been an option to set that date in the future.