Elon Musk says his days of trying to sleep less and work more are over — at least, relatively speaking. The Tesla, SpaceX and Twitter CEO, who referred to himself just last year as “fairly nocturnal,” has a history of pulling all-nighters and sleeping under his desk to get work done. Now, he makes an effort to sleep at least six hours per night, he said in an interview with CNBC’s David Faber on Tuesday. | CNBC Make It