I wonder what time Barack Obama, Nicola Sarcozy, Vladimir Putin and other presidents/prime ministers go to bed at. And how much sleep they get. Thinking about it, a study on how and why "sleeping" has changed over the years would be really interesting.
Medvedev: wakes up at 8, goes to bed at 2 or later. (http://www.kp.ru/daily/24089/320586/)
Obama: shows up at the office shortly before 9. ( http://www.nytimes.com/2009/01/29/us/politics/29whitehouse.h...)
G. W. Bush: early riser, goes to bed at 10 (http://abcnews.go.com/Politics/story?id=1474572)