DD1 was a march baby , preemie w/ development delay, she should have started pt in sept, ft in Jan. She just wasn't ready her then school accepted that and she spent an extra term at school nursery and went pt in Jan, ft at Easter (5.1) with the summer babies. DS1 was an April baby, but was so ahead, current primary took him 'early' (by the standards then, it changed this Sept to an all in in Sept intake, god am I glad my DC's missed that!) He should have been a pt Jan, ft Easter, but was taken pt Sept, ft Jan at 4.9, but he could easily have gone at 4.1, he was ready then. DS2 on the other hand, is a November baby, seriously delayed, didn't talk til 3.1 (first word) or walk til 3.6. HE had to start ft Sept as his 5th b'day was before xmas, and even now in Y1 he is already 6yo, but is lagging behind even the summer babies, I personally feel he is only just ready for reception, and could well do with repeating reception (not an option in our area). Different horses for different courses, but AFAIC MOST children are FAR too young at the 4.1 they are taking some of them in reception in my school now, my DS2 is the exception, NOT the rule, he's G&T, only reason he was ready early. DS2's 4.2 stepbrother really struggled on starting reception, and is still struggling, he's been excluded twice, he doesn't have the social skills he will have in a yrs time.