G, in NSW< they have 3yo and 4yo preschool. It is non mandatory for them to attend, but the Govt recommends that in the year before they start school that 4yo's do a minimum of 2 days per week. Where I live, 3yo's attend a maximum of one full day per week, which is from 9am to 3pm. From 4yo they can attend a max of 3 days per week from 9am to 3pm. DS2 is only attending 1 day per week this year in his year before school. The age cut off is July and they must be at school the year they turn 6. So for our September boys, they have to be at school next year, but for your Feb boy, he can be held back another year. My Feb boy started school the year he turned 5, so he was still only 4 for the first few weeks of school, but I could have held him back another year so he would have been nearly 6 when he started.