Carrie, not sure how it works really, legally I mean, it's going to be difficult for parents to grasp the laws around it when those doing the actual job can't grasp it either!
If they have a place for September, then why not for now? they cannot refuse to admit ds because they are full, being full is not a reason that withstands. If they are saying September it's probably because they know children are moving on / up. So makes me think they are saying september because they don't have the space now. Which isn't good enough. Not sure how you'd go around that though.
Ds place was for the September it was Easter they said he had a place, so not too long to wait and I didnt mind as such keeping him at old school for a few extra months, but then they said they could perhaps get him in earlier. And they did, he started in may.
Worse case scenario, 8 months. 6 weeks of that is the summer and then all the other breaks, I would say 4 or 5 months of actual school left? Maths not being my strong point, but roughly.