New research published online in the Journal of Epidemiology and Community Health says regular bedtimes can help children to perform better at school.
The study of more than 10,000 youngsters revealed their cognitive development is affected by inconsistent bedtimes.
Three, five and seven year-old children were associated with lower scores in reading, mathematics and spatial awareness.
The results were very similar both on boys or girls.
Professor Amanda Sacker, report contributor and member of the Department of Epidemiology and Public Health at the University College, in London, says sleeping is important.
"You just need sleep to consolidate all that you've learnt and experienced from the day before, so that this gets, sort of, laid down in your brain as memories and so on; so you just need to have sleep for that," said Sacker. "And also, people's body rhythms might be affected by inconsistent schedules."
Sleep practitioner Emma Janes also agrees on the importance of regular bedtimes and she says that some children need to be taught how to sleep.
"We learn to sleep. So everyone assumes we just know but for some children they need teaching it. And we know that children thrive on routine," said Janes. "They love to know 'what, when, where, why, how'. By changing that routine, we are going to impact on their sleep."
The research authors also point out that irregular bedtimes could disrupt natural body rhythms and cause sleep deprivation.
Scientists believe the lack of sleeping routines can also undermine the plasticity of the brain and the ability to acquire and retain information.
So, for children "early to bed" will surely make them "healthy, wealthy and wise."