I find that this confirms what we already know. It's hard to fit intense creative time into an 8 hour box.
A quote on Poincare's [1] working habits: "He worked during the same times each day in short periods of time. He undertook mathematical research for four hours a day, between 10 a.m. and noon then again from 5 p.m. to 7 p.m.. He would read articles in journals later in the evening."
I think we could find 100 other examples.
[1] http://en.wikipedia.org/wiki/Henri_Poincar%C3%A9
