Sleep and the daily rhythm by age: the national sleep guide and the 早寝早起き朝ごはん campaign

How much a child sleeps, and when, is one of the few things a parent can change at home that schools and doctors both care about. Japan's health ministry (厚生労働省, MHLW) published a national sleep guide in February 2024, the 健康づくりのための睡眠ガイド2023 (kenkō-zukuri no tame no suimin gaido, sleep guide for health), with a separate section for children. The education ministry runs the school-side campaign, 早寝早起き朝ごはん (hayane hayaoki asagohan, "early to bed, early to rise, and breakfast").

How long, by age

The guide quotes the American Academy of Sleep Medicine's figures and then sets its own recommendation for school-age children:

小学生は９〜12時間、中学・高校生は８〜10時間を参考に睡眠時間を確保する。

Age or school stage	Hours per day	Where the figure comes from
1–2歳	11–14	AASM figure, cited in the guide
3–5歳 (年少 to 年長)	10–13	AASM figure, cited in the guide
小学生 (小1–小6)	9–12	The guide's recommendation
中学生・高校生 (中1–高3)	8–10	The guide's recommendation

The guide warns that these hours may surprise parents: children up to high school need more sleep than adults, so a regular routine matters even more for them than for adults.

What changes as a child grows

The guide describes the pattern stage by stage:

• Preschool. Children nap, and their sleep habits are easily shaped by the parents'. The guide suggests the whole family aims for early bed and early rising. It says the need for a nap drops from about age four to five, and that for a preschooler who has trouble falling asleep at night, skipping the nap may be the better choice.
• Elementary school. Naps fade. The guide says

  小学生は早寝・早起きが得意ですが

  (elementary children are good at early to bed and early to rise). From this age it recommends keeping a fixed wake-up time and counting back from the recommended hours to set bedtime. Children start choosing their own bedtime, and parents are asked to help them leave enough time for sleep.
• From puberty. The body clock shifts later: the sleep hormone melatonin starts later, so bedtime slides and mornings get hard. Club activities, study, friends and devices add to it. Sleeping in at the weekend means no morning sunlight, which shifts the clock further. The guide says the years from puberty to working life are when late nights, short sleep and weekend lie-ins are most likely.

What the guide asks families to do

• Morning light. For young children, set a wake-up time and open the curtains. From elementary school, get daylight on the way to and at school, and keep the same wake-up time at the weekend.
• Breakfast. Skipping it pushes the body clock later, and late nights lead to more skipped breakfasts.
• Move, and limit screens. For 小・中・高校生, at least 60 minutes of physical activity a day and screen time of 2 hours or less. Avoid hard exercise in the hour before bed.
• Devices out of the bedroom.

  デジタル機器は寝室には持ち込まず、電源を切って、別の部屋に置いておきましょう。

• Agree rules at home. For late bedtimes with no real reason (watching one more show, one more game, chatting online), the guide says setting a sleep-schedule goal and family rules on device use can help.

What pupils in Japan reported

The education ministry asked about 23,000 pupils from 小5 to 高3 in November 2014. The figures are from that year:

	Elementary (小5–小6)	Junior high	High school
Asleep by 10 pm on a school night	49.2%	—	—
Asleep at midnight or later on a school night	—	22.0%	47.0%
Says their sleep is "not enough"	14.9%	24.8%	31.5%
Eats breakfast every day	89.3%	86.3%	81.9%

A dash means the ministry's summary gives no figure for that cell.

The survey also found, at every school stage, that children who often woke two or more hours later on days without school were more likely to say they were very sleepy in morning lessons.

When it is more than a late night

The guide says that when late nights and late mornings go on for a long time, getting up can become very hard, lateness can increase, and going to school can become difficult. It says this can become a sleep disorder of the body clock, the point where willpower alone can no longer push back against the shifted rhythm and the built-up sleep debt, and that it is important to consult a doctor as early as possible. The guide does not set a number of days; it is about a pattern that has lasted.

The school campaign: 早寝早起き朝ごはん

A national council for 早寝早起き朝ごはん was founded in April 2006, and the education ministry promotes the campaign with it:

文部科学省は同協議会と連携して、「早寝早起き朝ごはん」国民運動を推進しています。

The ministry's stated aim is to raise children's daily rhythm (生活リズム, seikatsu rizumu) as a matter for society as a whole, not only for each family.

What to do now

• Find your child's row in the hours table and count back from the time they must get up. That is the bedtime to aim for.
• Keep the wake-up time the same on school days and weekends.
• Agree where devices sleep at night, and write it down as a family rule.
• Protect breakfast, even a small one.
• If mornings have been a struggle for weeks and school is getting hard, tell the 担任 (tannin, homeroom teacher) and ask the school nurse (養護教諭, yōgo kyōyu) or your child's doctor. See also the 中1 gap: what the research says.