when we were there last September, the entertainment started at about 8:00 p.m. (which was what we were told when we checked in - they said it started at 8:00, give or take a few minutes.)
There was singing and/or instrumental music for about 40 minutes, then they took a break. After the break, they had a couple of Irish dancers out -- so that would have been about 9:00 p.m. for the dancers.
Don't know if that's the usual pattern, though, that was the first time we've been there.