Dailymail

Washington

From the best night’s kip being enjoyed on a Wednesday to rising the earliest on a Sunday, new data is giving fascinating insights into how the world sleeps.

Using statistics from Sleep Cycle app users, researchers have discovered that the earliest wake-up time worldwide is on a Monday in South Africa. While on Tuesdays, Americans rise at 7am and are in the worst mood all week.

Other countries that wake-up grumpy on Tuesdays include Singapore, Spain, Switzerland, South Africa and Brazil. The Sleep Cycle app tracks a user’s sleep as they go through a cycle of sleep phases. It uses the phone’s accelerometer to identify phases by tracking movements in bed and wakes users up during their lightest sleep phase, using a pre-defined 30-minute alarm window.

It has more than two million active users and gathered data for the study between 1 June 2014 and 31 March this year from users aged 18 to 55 in 47 countries. Other insights from this data include that the best sleep quality worldwide occurs on a Wednesday night. More than half (58 per cent) of the countries surveyed said they had the most restful sleep on this day, with China recording the highest sleep quality in the world that night. On Thursdays, people in the Middle East wake the latest and the happiest, and in Kuwait, Saudi Arabia and UAE in particular, users also reported the best mood on Thursdays.

Despite waking up grumpy on Tuesdays, by Friday the US sleeps in the most and wakes up happiest. The data revealed Americans typically don’t rise until 8:24am on Fridays and also report the best wake-up mood. Also waking up happier on Fridays are people in Costa Rica, Canada, New Zealand and Sweden. However, the majority of the world (71 per cent) wakes up in the best mood on Saturdays. Nearly 90 per cent of countries surveyed sleep more and wake up later on Saturday compared to any other day of the week.

While two thirds of countries said they spend least amount of time in bed on Sundays. Topping the list is South Korea where users only sleep 5 hours and 53 minutes on Sunday nights. Over the course of the week, people in Finland get the most hours sleep - on a Saturday with eight hours and two minutes, on average.

On the same night, people in Japan get an average of just six hours and nine minutes sleep. In terms of national average sleep quality, Slovakia topped the list. China was in second place followed by Hungary and the Czech Republic. The UK was in 45th place, while the US was in 49th.