My middle child is a late November baby and I started him at 5 in prep. He didn't like pre-school so I took him out of it halfway through but by the time school started he was anxious to get on with it and has never had a problem. My twins will be 5 in late January and I will be starting them in school the following week. TBH I did struggle with this decision but girltwin is ready and I couldn't hold her back. Boytwin I didn't think would be completely ready, he is speech delayed and this worried me so I had him assessed by the school (at 4 years and 4 months) and they have said he is absolutely ready for school already. He's very excited about it. However my children have always attended some form of daycare/preschool from aged 3 (apart from the last 6 months for DS2 when I withdrew him but this was an issue with the preschool, not with my son) and I think this has helped prepare them for school.