Birthday - Not Just About the Cake:
Summer swim is a seasonal sport. Almost all summer leagues choose a particular date by which ages are reckoned, and a swimmer's age on that day is their age for the entire season.
In the Colonial Swim League, the important birthday date is June 15th.
For example: if your 11th birthday is on June 15th, you are an 11-year-old for the entire season. On the other hand, if your 11th birthday is on June 16, you are a 10-year old for the entire season.
Why does this matter in the whole grand scheme of things? It matters because of the way the age groups are split up for League meets. Trust us, if you have a birthday on June 16th or shortly thereafter, consider yourselves lucky every couple of years when an Age Group changes (like from 9-10 to 11-12) but you still get to remain in the lower age group.
Your date of birth does not affect what Barrington practice group you are placed in.