
From memory it's counted from the first day of the show so if still pup then you should be ok.
I entered my girl in Junior at 18 months & 1 day at a Ch Show (we were the 3rd day I think. Whatever it was I triple checked the schedule ;-)). The judge (an experienced one)was told her age, she raised an eyebrow, smiled then gave me the class & Best Bitch :-D