I personally have never heard of this holiday, and there is not much information out there about it. But, what a great way to spend a day! Maybe it should be read "anything" today! Or, read "something" today?
Why not take some time out and read today? It's going to be a great day outside; take a book out and read on your break. Inhale that pre-fall air, get into the spirit of school and read something today.
Check out the following article about "Read a book day."