Delaware! 31 states and counting.
As far as school libraries, that's a really nice idea, and super duper if you are able to be open on Saturday. If you are a school library that wishes to participate and you can NOT be open on a Saturday, please keep in mind that Take Your Child to the Library Day can be scheduled to any day in February (and may have to be if the weather doesn't cooperate!) so please feel free to schedule a weekday celebration.
All that said, please let me know if you are a school library and I will make a special designation for you in our list of participants indicating you are a school library.