If Shannon were 2 or 3 months older than age limit, how about Mary who is 2 or 3 months older than Shannon, how about Debbie who is 2 or 3 months older than Mary. It can go on and on. That’s how kids become 18 months older than other kids. That’s why it’s called honoring a cut off date. This keeps all age groups within a year. Very easy to understand.