Many schools across the country start classes too early in the day according to the CDC, which just this week released a study emphasizing the harmful effects of starting a school day prior to the recommended time of 8:30am.

"Sleep can definitely effect children especially when it comes to school behaviors.  It can effect their demeanor.  It can effect their attention span.  It can effect their ability to focus.  So, getting them on an appropriate sleep schedule so they are getting the right amount of sleep is really important," said pediatrician Dr. Therese Linnon with Akron Children's Hospital.

Getting them on a schedule might be easier said than done, especially considering a lot of kids are still wrapped up in summertime and going to bed at odd hours.  To ease with the transition, Dr. Linnon recommends parents adjust their kids sleep schedule a little bit at a time.

"So, it usually takes kids about 15 minutes a day to adjust to their sleep schedule.  So, if they are off by an hour, you want to start about a week before you need to send them back to school adjusting 15 minutes per day," said Dr. Linnon.

Some studies show adequate amounts of sleep can increase productivity by up to 20%.  At elementary school age, kids should be getting 12 hours or more sleep a day.  Middle school students should have 10 hours to 11 hours or more and high school students should be sleeping at least 9 hours a day.

"They are expected to be more on target and more focused and so sleep becomes more of an issue.  They can come home and be quite tired even if they are sleeping the appropriate recommended amounts of sleep and it is ok to let them take a little rest in addition to sleeping through the night," said Dr. Linnon.

Experts warn against screen time prior to kids hitting the hay.  Things like watching TV and playing video games should be avoided an hour or more before your little ones doze off.