The most detailed study of night work, carried out by Daniel Hamermesh, an economist at the University of Texas at Austin and published by the National Bureau for Economic Research, compared 1991 with 1973 and found a marked decline in work between 7pm and 5am.

ECONOMIST: No more nine-to-five

Austin, Texas (CNN) -- For years, Connie and Daniel Roddy did all they could to support Livestrong, raising tens of thousands of dollars for the cancer charity founded by cyclist Lance Armstrong.

CNN: SHARE THIS

The Austin American-Statesman interviewed Rick Fuelling, who came up with the idea, and Daniel Mann of Active-TV Technology, who did the technical work.

FORBES: For $2.99, youth coaches get an app that tells parents, "Shut up"