How much time in preschool is ideal for a 4 year old?

My son is 3 this year and in preschool for 3 "half days" per week. A half day is really only about 2.5 hours. He's doing great there and loves it. My wife is a stay at home mom so we just send him there for the socialization aspect, not as a form of child care.Looking ahead to next year when he is 4, we are trying to decide if we should enroll him for more time. We could do 5 half days, or even some full days. I'm currently leaning towards 5 half-days, but my wife thinks sticking with 3 half days is fine.He's our first born so not sure exactly what would be best for a 4 year old. Anyone have any experience with this? via /r/Parenting https://ift.tt/2JpUmaR