It's been proven that happier employees are more productive employees, and many executives and human resource experts have said workers who enjoy more personal time tend to get more done when they are at work. Yet, most Americans are still on a five-day workweek.

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There is no question that people are not machines.

"If they try to work all the time, they not only become less efficient, but they get less done in more time," said Louis Maltby, president of the National Workrights Institute. "People who take two weeks off every year get much more done than people who never vacation."

It is hard to get everything done in a two-day weekend. It used to be that when people took Friday off, it might have been a problem, but that's not the case anymore, according to Maltby.

"If you're taking Friday off and something comes up that won't wait until Monday, you have your cell phone, you have email and you have text messaging. Your boss can get a hold of you and you can take care of whatever needs to be taken care of even if you're not in the office," Maltby said.

Most employees are responsible. They know what they need to get done, he added.

"If they have to get it done in four days rather than five, they'll work a little harder. They'll be more efficient because they want to get the job done," Maltby said. "There are a lot of things you can't get done on a weekend. People will be much better off having time off during the week to take care of things they can't do on a Saturday or Sunday."

While it's tough to directly graph how a four-day workweek would effect morale and productivity, it is not a secret that people who are feeling less pressured and better about their lives are more engaged and they work harder.

"Happy workers get more work done than miserable workers," Maltby said.