@Shiny_Trout865
Good question. We used August 1 as the age-check date because the last end-of-season championship meets are usually around that time. We could use an earlier date like July 1 to make the list more inclusive, but that would be less accurate. For example, a swimmer born on July 15 would already be 11 for an August 1 meet, so they should not be treated as a 10U record candidate at that point. On the other hand, using August 31 would be stricter and could exclude some swimmers with August birthdays who are still age-eligible for the main championship meets earlier in the month.
We know it is not perfect. August 1 is a practical cutoff, but it can exclude swimmers who age up just before August even though they are still eligible for earlier July meets, and it can include swimmers who turn 11 shortly after August 1 and are no longer eligible for later August meets.
