Yeah it has to do with racing age. All Thoroughbreds are rounded to January 1st so that they are eligible for racing sooner. So technically, an 18 month old could be considered a 2 year old depending on the month they were born.
My two girls, Ginisee and Demi have their birthdays today (although their real birthdays are in February)
Happy 18th Birthday Ginisee!
Happy 7th Birthday Demi!
Uma is the only one that doesn't have a bday today. She's 3/4 Tb and her birthday isn't until early April