When my son was an infant, I hired an online sleep coach to help me figure out why he wasn't sleeping well. It was the toughest year of my life. He was a miserable baby. Silent reflux. Colic. I don't know for sure what was going on, but he rarely slept more than two or three hours at a time. I was at my wit's end.
Donato FINALLY started sleeping through the night when he was a year old. His bedtime was between 7:30 and 8pm...because that's when I was going to bed. He eventually started sleeping until 6 or 6:30am. We have kept this schedule because it's working well. When Donato started pre-school a few weeks ago, we were worried whether he was getting enough sleep (he refuses to nap at school...but at home, he naps for almost two hours on weekends). He is very cranky when I pick him up at 3:45pm...so we are putting him to bed a few minutes earlier.
Your kids are probably on a different sleep schedule during summer...but if you're wondering what time your child should go to bed once school starts, here's a helpful chart.
Administrators at Wilson Elementary School in Kenosha, WI, created it when they realized more and more students were tired in school.