here
Interesting. When I lived in Queensland, Oz, a local high school (12+) did something a bit like this, where the lower half or so of the school started at 7.30am or was it 8 til 2-2.30pm; and the older DC started at 10.30 til 5 I think so the whole school was only in during the central 'core' hours. It means they all got a go on the facilities, and it benefited teenagers, starting at 10.30am, but not hanging around with mates after 2.30pm or 3pm for 2 or 3 hours of potential trouble-time, whilst parents were still at work.
It was very popular.