Children practice sleeping techniques at a kindergarten in Handan, Hebei province, on World Sleep Day. The day was launched by the International Foundation for Mental Health and Neuroscience in 2001. HAO QUNYING/CHINA DAILY

The educational?authority in Changsha, capital city of Central China's Hunan province, has changed the start time for schools from 8 am to 8:30 am. It has also instructed primary schools to adjust their hours to ensure children are able to get 10 hours' sleep and one hour of exercise. It has also instructed schools to reduce the amount of homework children have to do each day. Beijing Youth Daily commented:

The adjustment has been made according to statistics that show 85.6 percent of the pupils surveyed get up between 6 am to 7 am and 94 percent of them sleep for less than 10 hours a night.

The instruction from the local education authority has been seen as a bid to remove the burden of too little sleep and too much homework from the students as research has proved that a lack of sleep has negative effects on growing children.

Of course, increasing the length of time children sleep does not just rely on them getting up later, but also requires an early bed time which leads to another issue: how to lighten the burden of extra-curricular activities, including the children's written homework.

If students aim to finish all the homework they are given at present they are left with no choice but to work late into the night.

Therefore, the education authority is right to limit the amount of homework.

Ideally, homework should take no more than an hour.