The countries who get the least amount of sleep are Singapore and Japan, with an average of 7 hours and 24 minutes, with the Netherlands getting the most sleep at 8 hours and 12 minutes. Middle-aged men were more likely than other age groups and genders to have a bad night's sleep, the data showed.
The data also revealed that people "exposed to outdoor light go to sleep earlier and sleep more" than those who mainly experience indoor light. The researchers also found that age was the "primary determinant" of sleep timing and that a country's average bedtime, rather than its wake time, was what predicted sleep duration.
In 2014 , researchers found that the use of "light-emitting screens" before bed can cause disrupted, poor-quality sleep.
The researchers found that on average women got 30 minutes more sleep per night then men, thanks to both earlier bedtimes and later wake times.