Unreachable on Vacation? That's 'Beyond Stupid.'

Long working nights. Stress. Time away from loved ones. If this sounds familiar then you might be an entrepreneur.

While even hard-working business leaders sometimes need to get away and take a vacation, every minute you're ignoring phone calls and emails from clients costs you money -- money your competitors will gladly take.

So before you hit the road on your next trip, think twice before setting up that “out of office” automated email reply. It's "beyond stupid," says entrepreneur and sales expert Grant Cardone

As an entrepreneur, you have to "be open for business 24/7, 365," says Cardone. "If you're going to take a vacation, you don't need to announce it to the world. ... You don't need to tell your clients, 'Hey, I'm sorry, I can't talk to you today. I can't receive your money today. We're not open for business today.'"

Can you get away? Yes. Can you spend quality time with your friends and family? Absolutely. To do so, do you need to completely unplug from your business? Absolutely not, Cardone says.

The trick is simple. Set boundaries and schedule some time each day to check emails and respond to customers. All you need is a small amount of time that's dedicated to your startup. For Cardone, it's about an hour a day while on vacation.

"Nobody ever knows when I'm [away from work]," he says. "People think I'm working 29 hours out of a 24-hour day. That's the impression you need to create."

For more, check out the short video above.

Related: Successful Entrepreneurs Are Never 'Out of the Office'