Ludwig Van Beethoven was an early bird. Pablo Picasso? Not so much. And Franz Kafka, well, he basically subsisted on two long naps each day.
Some of the differences in creative schedules are granular. A select few, for instance, dedicated impressive portions of their day to exercise—Charles Dickens, in particular, who spend more than two hours exercising each day, was a work out fiend. Others, meanwhile, managed to make their art or creative work despite spending a good deal of their time working a separate day job (see Kurt Vonnegut, Wolfgang Mozart, and Sigmund Freud).
In terms of actual time spent working on their craft, Voltaire, who worked tireless and almost without respite throughout the day, appears to have set the standard. Others—most notably Pyotr Tchaikovsky—limited their work in order to spare more time for sleep, food, and leisure.
Everyone, of course, has allocated time for sleep. Just maybe not too much. Especially Mozart, Voltaire, and Freud.