My son's birthday is in the spring and he was one of the youngest boys in his class. I have a fall bday and thought my kid would be great shape having a spring birthday. (I hated being one of the youngest in my whole grade, so I wanted my kids to have spring birthdays.)

Many parents of kids with summer birthdays keep their kids out, especially boys. So he was so young compared to so many other boys. Academically, he was fine. In sports it was tricky because so many boys were at least 9 months older than him.

States like NY and RI have later cut offs and kids who move here from those states can be a year younger than their NH classmates.

Schools I've seen are very hesitant to let kids get past the cut off. They're concerned about academics but also the social emotional aspects of being younger now and in the years to come.