seems to vary, depending on where you live in Aust. In my state, i think the thing determining the age is, the kindy is subsidized for the four terms before the child starts school. Say your child is starting school the year they turn five, then they are eligible for four terms of subsidised kindy, during the year they turn four. Bilby started kindy when she was four (birthday in Nov, started in late Jan). She started school in the year she turned five (late Nov), started school in late Jan the next year.

kids must start school by the time they are six, so here, i COULD have held out for another year, if i so chose.