Sleepless in Singapore? Apparently so, according to a study released recently.

Singapore is among the cities in the world with the least hours of sleep, clocking an average of 6 hours and 32 minutes a day. At the bottom of the list is Tokyo, where people sleep for just 5 hours and 46 minutes per night on average. South Korea comes close at 5 hours and 55 minutes.

Who sleeps the most? People in Melbourne, with an average of 7 hours and 5 minutes per night, followed by London at 7 hours and 2 minutes.

These are some of the findings from a vast new dataset released to The Wall Street Journal by Jawbone, the makers of the UP, a digitised wristband that tracks how its users move and sleep.

According to WSJ, the data tracks hundreds of thousands of UP users from Beijing to Orlando and gives an interesting glimpse into sleeping patterns.

The report did not say how many cities were included in the study.

The study also found that the phrase "early to bed, early to rise" apply to people in Brisbane who go to bed earliest at 10.57pm and wake up earliest at 6.29am.

People in Moscow, on the other hand, hit the sack latest at 12.46am and are also the latest to rise at 8.08am.

But it should be noted that the findings are merely a reflection of UP users' sleep patterns rather than the general population. The gadget costs US$150 (S$187) each.

Almost all the cities on the list got less than the 7 hours recommended by the US Centers for Disease Control, the report said.

CITIES WITH MOST HOURS OF SLEEP

Melbourne, Australia: 7:05

London, United Kingdom: 7:02

Denver, Colorado: 7:02

Brisbane, Australia: 7:00

Paris, France: 7:00

CITIES WITH LEAST HOURS OF SLEEP

Tokyo, Japan: 5:46

Seoul, South Korea: 5:55

Dubai, United Arab Emirates: 6:32

Singapore: 6:32

Mexico City, Mexico: 6:32