World Sleep Day falls around 春分 (shunbun, the spring equinox) every year — the next one will be March 13, 2026 — but sleep-deprived Japan celebrates 睡眠の日 (suimin no hi, Sleep Day) twice a year: March 18 and Sept. 3. The fall date was chosen according to rhyming wordplay. ぐっすり (gussuri), which is the onomatopoeic sound for sleeping, sounds similar to nine and three. Coincidentally, ぐっすり also phonetically sounds like the English “good sleep.”
最近ぐっすり寝れてますか？ (Saikin gussuri neretemasu ka? Have you been getting good sleep lately?)
Recent joint research by sleep-tracking app Pokemon Sleep and the University of Tsukuba revealed that 16% of 80,000 app users indicated ソーシャルジェットラグ (sōsharu jetto ragu, social jet lag), more formally known as 社会的時差ぼけ (shakai-teki jisa boke). The report estimated that the decline in labor productivity caused by social jet lag costs Japan’s economy roughly ¥1 trillion ($6.8 billion) annually.
