A regular bedtime schedule is unquestionably helpful for parents, but a new study has found it that it may be even more beneficial for their children.

British researchers interviewed mothers when their children were ages 3, 5 and 7, asking how often their children had a regular bedtime: always, usually, sometimes or never. The mothers and the children’s teachers also completed questionnaires about behavioral difficulties.

Almost 20 percent of 3-year-olds had no regular bedtime, compared with 9.1 percent of 5-year-olds and 8.2 percent of 7-year-olds. After controlling for many social, economic and parental behavioral factors, the scientists found that children with a regular bedtime, whether early or late, had fewer behavioral problems. And the longer irregular bedtimes persisted, the more severe the difficulties were.

The study, published Monday in Pediatrics, also found that children who had irregular bedtimes at ages 3 and 5 had significant improvements in behavior scores if their bedtime was regular by age 7.

Still, the lead author, Yvonne Kelly, a professor of lifecourse epidemiology at University College London, warned against exaggerating the importance of the findings.

“Getting kids into a regular bedtime routine does appear to have important impacts on behavioral development,” she said. “But there are lots of things that have beneficial effects. Having a regular bedtime is only one of them.”