Elon Musk is so busy running both Tesla and SpaceX that he schedules his day out into five-minute slots.Musk finds time to sleep six hours a night, despite working between 85 to 100 hours each week.The billionaire finds time to spend with his five children during the workweek, but said in 2013 that he still checks his email when he is with them.Visit Business Insider's homepage for more stories.Elon Musk is one busy guy.The billionaire CEO of Tesla and SpaceX generally spends a full workweek at each of his two companies, wolfing down lunch in five minutes and skipping phone calls for productivity's sake.So it's not surprising that his daily life is pretty jam-packed.Based on previous interviews, Business Insider pieced together an estimation of what an average day looks like for Musk.SEE ALSO:Robert F. Smith on becoming the richest black man in America, what companies get wrong about diversity, and what he's doing to help mint more black billionairesDON'T MISS:Elon Musk made almost $12 billion in the past week as Tesla's stock soars. Here's how the eccentric CEO makes and spends his $45.2 billion fortune.Musk kicks off his day bright and early, rising at about 7 a.m. In a Reddit AMA, he said he usually gets "almost exactly 6 hours on average."Source: Business InsiderMusk usually skips breakfast. Occasionally, he will slow down long enough to grab a quick coffee and an omelette.Source: Auto BildOne thing he always makes time for, no matter what' Showering. He once wrote on Reddit that it had a greater positive impact on him than any of his other daily habits.Source: Business InsiderOnce he's up, Musk launches into a blistering schedule that breaks his time into a series of five-minute slots. The entrepreneur has been known to work 85 to 100 hours a week, and he estimates that 80% of his time at work is spent on engineering and design.Sources: Inc., The Independent, Y CombinatorNo two days are the same for Musk. He spends Mondays and Fridays at SpaceX in Los Angeles. On Tuesdays, Wednesdays, and Thursdays, he heads to the Bay Area to work at Tesla. Quartz estimates that he spends an average of 42 hours a week working at Tesla and 40 hours a week working at SpaceX. He also told Y Combinator that he usually spent about half a day working at the artificial intelligence nonprofit OpenAI.Source: Quartz, Y CombinatorOn the weekends, it's more of a toss-up. Sundays are usually spent traveling or staying at his Bel Air mansion. On Saturday, he either works at SpaceX ...Source: Business Insider... or spends time with his five young sons. Speaking about his kids in 2013, he said: "What I find is I'm able to be with them and still be on email. I can be with them and still be working at the same time ... If I didn't, I wouldn't be able to get my job done."Source: Business Insider, Business InsiderMultitaskingis a crucial part of Musk's strategy, which he calls "batching." Musk often works on his phone while sitting in meetings.Source: Inc.To keep his work day on track, Musk forgoes most phone calls in favor of email and texts. He also prefers to use an obscure email address to prevent people from spamming his inbox.Source: Inc.He doesn't spend much time on meals. Musk usually takes his lunch during a meeting, and he manages to wolf it down in just five minutes.Source: Auto BildHe ends up getting most of his calories later in the day. "Business dinners are probably where I eat way too much," he told Auto Bild.Source: Auto BildWhen it comes to food, one of his favorites is Diet Coke, thanks to "some infernal ingredient." Musk told Auto Bild that he had since cut back on the soda. CBS previously reported on the tech mogul's preference for French food, barbecue, and whiskey.Sources: Auto Bild, CBSTo stay in shape, Musk usually hits the gym about once or twice a week.Source: Auto BildDespite his busy life, he also carves out enough time to read. Some of his favorite titles include the fantasy classic "The Lord of the Rings," biographies of innovators like Benjamin Franklin and Albert Einstein, and an obscure 87-year-old history book on adventurers called "Twelve Against the Gods."Sources: Business Insider, Business InsiderMusk may be a bookworm, but that doesn't mean he can't party. The entrepreneur's legendary bashes have included a birthday party at an English castle that turned into a big game of hide-and-seek, and inviting a knife-thrower to pop balloons that he held between his legs.Sources: Entrepreneur and Business InsiderWhen all is said and done, Musk usually doesn't crash until 1 a.m. That late bedtime isn't too surprising for a man who's busy trying to send humans to Mars.Source: Entrepreneur Click here to read full news..