The individual states in the US set their kindergarten entrance
standards. I can speak only of California "for sure".
If a child will turn 5 between Sept. 2nd and Dec. 2nd, s/he is
enrolled in "TK", or Transitional Kindergarten. The premise is
that they will then spend 2 full years in kindergarten.
A child who turns 5 before Sept. 2nd will be enrolled in
regular Kindergarten, and will usually only spend a year in
Our kindergarten day is full day. My maximum amount of students
is 25, and I do not have another (paid) adult in my classroom
unless a child is a mainstreamed special education student and
his/her IEP requires an aide.
Other states, like Missouri and Alaska, have an August date for