When did Irish dancing start for kids?
9:00am? The fifth century? At four years old?
I don’t know what you mean.
If you can walk you can dance, and as a people Irish people have been dancing since before they were Irish people - back when we called them invading oppressors.
Most stuff isn’t documented as what you know and love as Irish dancing until the last few centuries, but the Celts and the Normans, were known to tap their feet. And the fifth century is seen as the golden age of Irish poetry and music. With all that music going on what else would you do but dance - write poetry?