Then it changes every year Dave.

The Track and Field and the Cross Country has the same system but with 31st August. The only real difference is road. Champs road still also have 31st Aug and the reason road is age on day of race is most likely that there are very few specific road races for juniors.

We also have the same system in schools athletics whether track and field, cross country or fell.

There is no real reason for change.