You''re going to have to explain why New Year's day has any importance in athletics. And the September 1 day has no meaning when we're talking about club/rec sports rather than school sports. Also, the more dates you include, the more arbitrary those dates become.
The first step is to acknowledge kids, using 2027's as an example, born prior to 9/1/2007 shouldn't be 2027 athletes regardless of their enrollment. These are the double holdbacks and there are 5-10 in hoco in the 8th grade division every year.
The next is to have a verification system with age and class required. I have yet to run across one of these national all star teams who aren't using 9th graders on the 8th grade roster. The only 2 tournaments where that didn't happen was WSYL and The Circuit. They both verified.
If the system remains class-based, I would go further and eliminate 2007 birth dates altogether and maybe roll it all the way to June1. If the system were to magically change to age-based, I would argue for a February 1 and August 1 "age-up" date. This would capture the spring/summer and fall/winter season. This would also allow some kids to gain back some age and maturity disadvantages. | 
