6, 7.5 or 9.

I love naps. Don't often do it, but I love them. So here is some information:
http://www.mentalfloss.com/blogs/archives/15934
Oh, and the title? I follow the 90 minute thing. So those are my choices for how long to sleep at night. I prefer the seven and a half, but if I can't do that I'll do six, intead of seven. It works. Honest.