Last August 15, we attended the annual Family Day at our kid's school. We were there at 7:30 a.m. and the first order of the day was the general assembly for the parents. It started at 9:30 a.m. or thereabouts. It took less than the waiting time and the subsequent games, even less.
It's probably unfair to compare but the only experience I can cite is that in my kid's former school. This was a smaller school, definitely, and maybe that's why it was better organized (but I still think this isn't an excuse).