It may seem like the 40-hour workweek has been a standard in our society forever, but, in reality, it's a fairly new development. For a long time, people worked 12+ hours a day, six days a week. It's only since the mid-20th century that eight hours a day, five days a week has been the norm, and there's reason to think our workweek should be even shorter.

In recent years, many businesses have begun to offer employees shorter workweeks. At 43 percent of companies, some or all employees are given the option to work four days a week. While the practice is still pretty new, many have found that it's beneficial, not just for employees, but for their companies as well. Here are some reasons why the four-day workweek makes sense for everybody.

Increased Productivity

Well-rested employees are more productive. Happy employees are more productive. Shorter workweeks make your employees better rested, happier, and more productive. Jason Fried, the CEO of software company 37signals, wrote an op-ed in the New York Times touting the productivity gains his company experienced when transitioning to a four-day workweek for the summers.

Businesses have one of two popular options when scheduling a four-day workweek. They can do 8-hour days, 32-hour weeks, relying on increased productivity to make up the difference. They can also work longer hours during the four days (a 4-day, 40-hour week arrangement), getting more work done potentially and still keeping that traditional 40-hour workweek.

Better For Families

Everyone knows how hard it is to achieve work-life balance. A recent survey revealed that nearly two thirds of employees agreed that work-life balance is the most important factor in overall satisfaction. The four-day workweek makes it easier for parents to balance the demands of work and raising children.

This has already become a common practice in certain fields, including medicine. For instance, 44 percent of female doctors now work four or fewer days a week. Of course, it can also be good for men that want to spend more time with their families. Especially if employers are flexible, one parent can take Fridays off, one takes Mondays off, and they have plenty of time with their children.

Improves Employee Retention

Employee turnover can be extremely difficult for businesses. Losing talented people, and then having to spend time and money identifying and training replacements, can be a major burden. For companies working on significant long-term projects, retaining key talent is absolutely vital.

For companies with limited resources that can't afford raises or other benefits, a four-day workweek can be a good way to make themselves more appealing than other employers. As noted, the productivity gains mean you're not sacrificing much in the way of total work accomplished, so it's a fairly low-cost perk.

Stimulates Creativity

We are living in an innovation age. The most successful companies are the ones that consistently come up with creative, new ideas. Ideally, you want everyone in your company to be capable of contributing creative ideas. Giving everybody in the company a longer weekend allows them more time to recharge, get out in the world, and stimulate their creative impulses.

Nothing deadens creativity like spending all your time day after day working on the same thing. Going all the way back to Newton theorizing gravity sitting under the apple tree, there's a long tradition of creative geniuses doing their best work in their downtime. Unshackling the brain from set locations, schedules, or regimented processes allows it to make new, unexpected connections and come up with new ideas. A four-day workweek leads to more creative, more satisfied employees who are in a better position to do their best work.