Those who successfully pull off a "side hustle" (a passion project launched in addition to your day job) know that time management is key. So is keeping yourself from having a total breakdown due to lack of sleep and brain burnout. While a side hustle can be a big undertaking, it's probably nothing compared to leading two wildly successful companies. Jack Dorsey makes it seem effortless as he runs both Twitter (as Executive Chairman) and Square (CEO) during an insane 80 hour workweek. How does he do it? He recently revealed the secret to keeping his 16-hours on the job from becoming a hot mess: themed workdays.

Monday is devoted to management meetings and "running the company" work, while Tuesdays are all about product development. Marketing, communications and growth are the focus of Wednesdays, developers and partnerships on Thursdays, and finally, fun Fridays are all about the companies and their culture. But he doesn't stop there — Dorsey actually schedules his weekends too. He spends Saturdays hiking, while Sundays are for "reflection, feedback and strategy." I'm tired already.

What lessons and tips can you take away from Jack Dorsey's incredibly organized schedule? Find out after the break.

• Automate your life — Ever wonder why Steve Jobs wore the same thing to work everyday? It was so that he could focus on what needed to get done instead of worrying about what he wore to the office. Planning a week's worth of wardrobe, meals, and workouts ahead of time save you stress and precious minutes (not to mention money). Sure, it may seem a little OCD at first, but at least you know you won't have to stand in front of your closet for 20 minutes trying to piece an outfit together. And think of all that cash you'll save by bringing your lunch to work!
• Work in blocks of time — Time management and an organized schedule is necessary to keep a busy day from snowballing into a runaway train, and sectioning off your time for work and rest is a great way to keep from getting overwhelmed. For every 50 minutes of work time, take 10 minutes to get up, walk around, stretch, or just zone out. Be unproductive. A desktop or smartphone timer can come in handy for this.
• Devote certain tasks to specific days — You can also set up your week like Jack, where every day is devoted to accomplishing tasks in different areas of your business. If you're running a side hustle, this will definitely keep you on track during your "off the clock" hours as well. For example, Tuesdays can be devoted to the design of your businesses website, Wednesdays can be all about writing a weeks worth of blog posts in one day, so on and so forth.
• Treat yo self — No time for fun and games when you're trying to dominate your business? Bullocks. Take time to get a massage, go for a hike, or take your dog for a proper walk. Running yourself into the ground won't help you achieve your dreams. If anything, stress has been linked to such ailments as heart disease, digestive problems, insomnnia, autoimmune issues, even eczema, and that doesn't look good on anybody.

UPDATE: Forbes posted this video of Jack outlining his work week at Techonomy 2011:

How do you manage your time? Any tips for someone trying to hustle on the side?