Making sure kids go to bed on time helps them get the sleep they need, according to a Canadian study reported by Reuters.

Just encouraging kids by reminding them about bedtimes may not work the way parents expect it to, the study also found. When parents relied on reminders about bedtime without enforcing the rules, children were 71 percent less likely to get the minimum recommended amount of sleep during the week.

“On weekdays, bedtime rule enforcement, not encouragement, was conducive to children achieving sufficient sleep,” Manson said by email.

Depending on the age of the child, the proportion of parents reporting that their child met the Canadian sleep guidelines ranged from about 68 percent to 93 percent on weekdays and from 49 percent to 86 percent on weekends.

The number of children getting the minimum recommended amount of sleep increased from ages 5 to 9 but then declined from age 10 to 17, according to the results published in BMC Public Health.

Fifteen-year-olds had the biggest variation between weekday and weekend sleep, with 38 percent fewer kids getting the minimum recommended amount of rest on weekends than on weekdays.