Back in the 1960s, advertising agencies in New York began noticing a dip in employee productivity on Fridays during the summer months when the hot summer sun caused people to shift into weekend mode before the workweek was over. Summer Fridays, as they were called, soon shifted into other industries. A 2012 study by Ultimat Vodka, however, revealed that only 12 percent of adult workers experienced the benefit of Summer Fridays. It seems as employers began demanding more work and longer hours, the Summer Fridays perk went out the window.

This is a shame, since the Ultimat Vodka study showed employees who benefited from summer hours were happier and more productive. Eighty-seven percent of those who had summer hours said this benefit contributed to a healthy work/life balance and 76 percent agreed Summer Friday policies were an effective tool to boost productivity. Indeed, for those who crave a weekend at the cottage, putting in a couple of extra hours from Monday through Thursday in exchange for a short day on Friday, or taking Fridays off completely, seems like a fair trade off.

Given that employee productivity during the summer takes a dip anyways, this seems like a good trade-off for business, too. A Captivate Network survey showed workers were up to 45 percent more distracted during the summer. Offering flexible hours may help counteract that. A study by Opinion Research Corporation showed 66 percent of employees who have summer hours perks felt more productive as a result of this flexibility.

Related: How to Create a Formalized Flexible Work Program for Your Company

David Heath, CEO and Co-Founder of the sock company Bombas, says flexible summer hours not only encourage work-life balance but helps to build trust with employees. “Our policy is basically that if you need to leave early to get somewhere, you come in early to finish your work or make sure all of your responsibilities are handled before you leave. It shows your team that you trust them to handle their own responsibilities,” he says.

Jodan Menashy, co-founder of the bookkeeping service Bench, says his company has summer hours all year long. “We like to focus on managing people’s efforts and reducing the focus on their actual physical input,” says Menashy, who believes that people will perform at their best if they aren’t forced to confine themselves to a pre-set office “norm.” The mandate “Enjoy Independence” was created by Menashy in an effort to empower employees to act as though they were independent entrepreneurs and manage their own workload, while working according to the pre-defined goals of their department.

Here’s how you can implement flexible hours in your company:

Allow employees to work to their peak time.

While some people are early birds, others perform at their best during the afternoon hours. Flexible hours means everyone can determine for themselves when they are going to be most productive.

Survey your team.

Ask your employees what they would think about flexible summer hours. Your team may think coming in early or staying late Monday through Thursday in exchange for an early Friday is just the ticket, or they might desire telecommuting on Fridays to avoid the commute to the office.

Related: An Open-Handed Vacation Policy is a Great Perk for Employers

Set parameters.

“We set loose parameters to allow employees to create the ideal work environment for them,” says Menashy. But to ensure collaboration can still take place, Menashy recommends setting some mandatory work hours. At Bench, all members of the engineering team must be online and available between the hours of 11 and 3.

Don’t fixate on exceptions.

Many businesses fear flexible hours because they worry employees will abuse the independence they provide, but Menashy says it’s typically the minority who abuse the newfound independence summer-flex hours provides.

“In the end, if people are abusing it, they’re probably not the right people to be in your company in the first place,” he says. “In the meantime, you’re building an experience for the 99 percent of people working for you”.

Start out slowly.

Rather than implementing a full-time flexible-hours policy right away, start out with a test for a month or two, measuring team productivity throughout the test. “The best way to insert flexibility is to also enhance your accountability,” says Menashy. Bench is increasingly investing in accountability systems that allow team members to state their goals on Friday for the following week and keep track of their productivity throughout the week to see where they’re falling short. This not only helps to relax management efforts, but ensures flexible hours are working for everyone on the team.

Related: Your Workers Want Work Flexibility But Companies Benefit Most