My dog will be exactly 18 months on the day a champ show is held, can she still go in the junior class?

Rose

Yes if that is the first day of the show
It says not exceeding 18 months of age on the first day of the show, or something close.

Think the word that causes the problem is 'exceeding'

The thing that used to confuse me when I started was if the 'months' were calendar months or periods of 28 days. No idea why I make life so difficult for myself.