I read this book aloud to my 13-year old son, who also gives it 3 stars. 
 The premise drew me in: After Wednesday comes Grunsday, an extra day of the week that only some people (Transitioners) visit. Others only live in Grunsday, experiencing one day to most people's seven days. This got me daydreaming about all the projects I would accomplish and the fun things I would do if given an extra 24 hours, until I discovered that this fictional extra day comes with no electricity, and electronic devices do not function. 
 Jax, a 13-year old orphan, is sent to live with the irresponsible Riley, not much older than Jax. After his first transition to Grunsday, Jax meets new people, and slowly begins to understand the hazards of his new world. The references to Arthurian times were a neat touch, and added some depth to the background story. 
 Overall I felt it was just okay. The premise, as I mentioned, I liked a lot. The writing is good, though some of the analogies were a bit odd. That's alright; they provided some comic relief for my son and me. Most notable was the description of a man's face as being as thin as tissue paper, or something. My son didn't care for Jax, and it was too conflict oriented for me. 
 If you like the idea of the book, and you're down with a stereotypical bad guy and a multitude of clan wars, give it a try. I was happy to finish reading it, but won't try any sequels.