Four in March? Shouldn't he be starting jk then in Sept? Most children I know start jk at 3-if born later in yr,or 4 if born early in yr. I care for a boy who will be 4 mid Feb and still naps (granted he comes at 645am) and will be starting jk in Sept. Same as other friends children I know.
It depends on where you are. Where I am there isn't a j/k. There is only kindergarten and they start at either 4.5 or 5 depending on when their b-day is.