What’s the latest you’ve ever stayed up reading a book? Is staying up late reading a usual thing for you?

I've stayed up all night to finish a book.  Two come to mind: Harry Potter and the Deathly Hollows and Eclipse.  I was so into the books that I just kept on reading.  Unfortunately, the day after reading Eclipse I still had to be at work and teaching by 8am.  That was killer!

I am finding that my advancing age is cutting on the ability to stay up reading all night.  Eventually my eyes tire out and I can't even see the words on the page.  I try not to stay up too late reading.  But it does happen sometimes.