My mom's birthday was also October 3rd, and her school system in Massachusetts also had the same cutoff. Her parents got around it by sending her to Catholic school so she could start kindergarten at age 4.

She so very much hated being one of the very youngest kids every year that when the possibility of me skipping a grade came up she vetoed it because was already one of the younger kids in my grade..and I was in my 30s before she admitted it had been suggested, twice!

My younger brother went to Readiness (anymore remember that? In the late 80s it was an extra grade between kindergarten and first grade) because he had at that point untreated ADHD, and she only agreed to let him skip 6th grade because he would be with kids the same age as him.

I understand my mom's stance about not wanting to set us up to be the least mature in our classes. Of the 4 kids I knew who graduated high school at 17, only one of them graduated college 4 years later.