I agree with starting at 7.
In this area they get nursery places at 3 and they are attached to schools, my school make it clear that absences are not acceptable, which I totally resent, how can you make a 3 rip year olds school attendance mandatory? I would much prefer them start officially at 7. My oldest has autism and so all the things the suggest children b able to do before school he fails on, it's far too young to push children into a one size fits all system.