Most of us know Rihanna best as a pop star with a string of hits under her belt. But the singer isn't just responsible for the soundtrack to your workouts and beach getaways. She also runs a fashion and beauty empire that, according to Forbes, recently made her the richest female musician on the planet.

Going from troubled beginnings in Barbados to being bigger than even Beyonce takes a whole lot of hustle. Besides her music and fashion lines, Rihanna runs Fenty Beauty, the makeup business she developed in partnership with French luxury giant LVMH.

The company "generated an estimated $570 million in revenue last year, after only 15 months in business. The entire operation is worth, conservatively, more than $3 billion," reports Forbes. Rihanna owns half of that.  

All of which adds up to one simple truth: Rihanna is superhumanly productive. How does she juggle it all and stay sane? She recently opened up about her approach to work-life balance to her Ocean's 8 co-star Sarah Paulson for Interview magazine (hat tip to Business Insider).

The letter "P" to the rescue

Celebrity watchers will find juicy details about her personal life in the interview, but the conversation also offers plenty to interest those most focused on Rihanna as a business woman. For instance, she's just as crazy busy as you'd expect.

"I will work all day in a meeting, leave that meeting at 1 or 2am, and then come home with a tiny group of staff and work until 5, 7am," she tells Paulson. "I don't have a sleep pattern. I have sleep pockets. I fit it in when I can." 

That sounds like a recipe for burnout, but Rihanna claims she's loving her career as much as ever after recently revamping her approach to managing her energy and her time.

"It's only the last couple years that I started to realize that you need to make time for yourself, because your mental health depends on it. If you're not happy, you're not going to be happy even doing things that you love doing. It'd feel like a chore. I never want work to feel like a chore. My career is my purpose, and it should never feel like anything other than a happy place," she explains.

Rihanna now insists on making time for the all the other things in life, from grocery shopping to spending time with her boyfriend or flying to Barbados for a concert. "Just like I nurture my businesses, I need to nurture this as well," she insists.

How does she fit in occasionally being a normal person and just enjoying life? "I'll shut things down for two days, three days at a time. On my calendar we now have the infamous 'P,' which means personal days. This is a new thing," Rihanna explains. 

Your schedule isn't going to magically fix itself. 

This obviously isn't the most complicated system in the world, but just because it's simple doesn't make it any less profound. There are several lessons even us non-superstars can learn from her simple 'P' day trick.

First, no one is going to control your schedule but you. You can spend your whole life waiting around for that mythical lull where you'll suddenly have time to breathe, see your kids, and catch up on your sleep. Chances are excellent, however, if you don't have the kind of life where that's come naturally to you before, it's not going to come naturally to you in the future either. You need to tackle your fear of missing out or being proven less essential than you think you are and take control of your own schedule so that it actually lines up with what you say your values are.

Second, as Rihanna eloquently expresses, self-care and a life outside work isn't an indulgence. It's an essential. Research shows that having activities outside work will make you smarter, more creative, and perhaps most importantly, more resilient as well.

Having a life, in other words, actively benefits your career. Which might be why so many entrepreneurs who have successfully played the game for years without burning out swear by the little things, from simply doing the dishes or hanging out the laundry each day, to making time for a beloved pastime like surfing, sailing, or horseback riding.

So take a look at your schedule. If it's crammed with work from morning to night every day maybe you should steal this trick from Rihanna and boldly start penciling in a few Ps.