Little Athletics goes by the ‘Under X’ system., where the age group is set by the age of the athlete as of Jan 1st midway through the summer season.
In other words, if your athlete is 7 years old as at 1 January 2024, they wil be in the U8 age group for this current season.
Still not 100% sure? An age group calculator can be found here, which hopefully helps you decide which age group is correct.