Hi L2C, I'm sorry to say your info looks correct. According to their website they are open Tuesday through Sunday 08:15 to 18:15, but it may be worth emailing them on email@example.com in case this is a seasonal thing.
Last Cruise: Azamara Journey August 2014
Next: Queen Victoria November 2014
Followed by: Queen Elizabeth December 2014 and Minvera April 2015
Just want to let anyone know that is planning to see The David in Florence -- if you are there on Monday, the museum is closed. It is closed every Monday, year 'round. Just received a reply from the secretary's office about that today.