11 Birthdays by Wendy Mass. Everyone loves birthdays, but they don't want to have to keep repeating it, do they? That's what happens to Amanda in this novel. She and Leo were born on the same day and have been best friends ever since. But their friendship had a sudden ending on their 10th birthday when Amanda found out Leo didn't really like her (as a friend, of course).When her birthday comes back around, she thinks it's just gonna be another year. Boy, was he wrong about that! She wakes up the next day and finds out her birthday keeps repeating. What is she going to do? Read this book to find out. It's also on the 6th grade summer reading list.