You don’t have to wait till you’re sick to take a sick day.

Mental health is just as important as your physical health in the workplace, according to West Coast-based CEO Ben Congleton, whose viral response praising an employee for taking a personal day to focus on her well-being received rave reviews from the internet and even Facebook COO Sheryl Sandberg.

“We’re paid to bring our brains to work to help solve problems,” Congleton, who works for the live chat software company Olark in Palo Alto, CA. told Moneyish Tuesday.

“When we’re unable to do that, to me, that’s a reason why sick days are created in the first place.”

One of Congleton’s web developers, Madalyn Parker, tweeted an email exchange frankly telling her co-workers she was going to use a sick day to focus on her mental health — and she was blown away by her boss’s supportive response.

“I just wanted to personally thank you for sending emails like this. Every time you do, I use it as a reminder of the importance of using sick days for mental health – I can’t believe this is not standard practice at all organizations. You are an example to us all, and help cut through the stigma so we can all bring our whole selves to work,” he wrote.

Parker is hardly alone. One in five adults have a mental health condition, and each day, 1 million U.S. employees miss work due to stress in the workplace, according to the American Institute of Stress. And it doesn’t help that 70% of employees say you have to work late to get ahead with 62% of employers agreeing, reports Randstad, a recruitment agency.

But Congleton hopes to change the stigma of feeling guilty for taking care of yourself.

He defines a personal day as time for self-improvement. So you should use one when you feel overwhelmed and need time to clear your head, or just to be with family.

“I don’t mind having crunch periods every once in awhile when people are working hard, but carving time out for self improvement is what helps performance long term,” he says.

And the internet seems to agree. Parker’s tweet was re-tweeted more than 10,800 times since it was posted on June 30, and some users thanked Congleton for giving them hope that they don’t have to feel bad about dealing with stressful conditions like anxiety and panic attacks out of the office.

“I’m gonna have to start job hunting soon and I’m mentally ill & have panic attacks. Thanks for giving me hope that I can find a job as I am,” tweeted one user.

Others pointed out the alarming stigma some bosses associate with serious mental health issues.

“I once called in to take a mental health day…my boss told me anxiety isn’t a real illness and that I needed a doc’s note,” tweeted Danielle Willette.

Sandberg — who’s known for listening to employee needs, like implementing an extended paid bereavement leave that gives workers more time to grieve during difficult times, and paid family leave — also recognized Congleton. The “Lean In” author posted this on Facebook in response to the viral story:

But for Congleton, it’s just business as usual.

“It’s nice to be one of the people that broke through the noise and got it out there.”