Around the end of each year's rainy season in July, it's common for the media to run articles on the subject of sleep. Hot weather is not the only factor that makes Japan less conducive to sleeping in summer. Since daylight savings is not practiced, the sun rises before 5 a.m., affecting many people's sleep patterns.
If more sleep were desirable than less, it would seem that Japan does not fare very well in international comparisons. In a survey undertaken in 2009 by OECD, out of 18 member countries, Japanese, with an average of 470 minutes (7.8 hours) per night, ranked 17th, ahead of South Koreans by one minute. The top five countries were France (530 minutes.), the U.S. (518), Spain (514), New Zealand (513) and Turkey (512).
"The short sleeping time of Japanese," Weekly Diamond (July 1) writes, "cannot be said to be unrelated to long working hours." The issue devoted 36 pages to sleep, starting with the socio-economic implications.