I tend to read in the evenings, if I'm just reading for the sake of getting through some chapters.
When I'm on a book I can't put down, I've been known to stay up all night, or skip class during the day just to get through the book as quickly as humanly possible.
I discovered the Twilight series about 4 weeks ago, and sadly, despite the fact that I really think they're poorly written, I love them. I read all four books (1000+ pages) in 3 days. Skipped class, left an essay til the day before it was due, just ploughed through them.
=D