No sir. All thirteen!

Prerequisites: Given that it's an anniversary celebration, I'd recommend having seen as much of the show as possible up to this point for the full experience.

Spoilers!
I'll fully admit that some aspects of The Day of the Doctor aren't my favorite thing. I would have vastly preferred the Eighth or Ninth Doctor to be the one who had actually ended the Time War, the Time War itself is portrayed a little too much like conventional warfare for my tastes, and the whole pseudo-retcon of whether the Doctor actually committed genocide is something I'm split on. Still, it's remarkable to me just how much of this special does work, and I love it to pieces. It's cinematic, bombastic, and contains some of my favorite individual moments in the entire series (Tom Baker's Curator cameo is particularly touching and respectful). This is some great stuff, and it's one of the most rewatchable episodes for me.