(NEXSTAR) – Thursday is the new Friday at 38 companies across the United States and Canada that are testing a shorter workweek in hopes of boosting productivity while keeping employees happy.

The companies are participating in a six-month trial in collaboration with the nonprofit 4 Day Week Global and researchers from Boston College.

“We establish their baseline before the trial,” explained Joe O’Connor, CEO of 4 Day Week Global. “So we determine what their company’s performance looks like on a range of different metrics such as revenue, productivity, energy use, employee turnover, levels of absenteeism and sick leave, as well as the well-being of their employees.

These baseline levels under the five-day work week will be compared to levels after testing the reduced work week.

Exactly what each company’s schedule looks like can vary quite a bit, O’Connor said. “Our prerequisite is that it must be a real reduction in working time. It cannot therefore be four 10-hour days. It can’t be the same hours compressed into four days,” he said.

Most employees will opt for a four-day work week — and therefore a three-day weekend — when given the chance, O’Connor said. But he noted that a minority of employees like to spread their 32 hours over five days, giving them the opportunity to spend more time with their children in the morning and after school.

No matter how they reduce their workweek, employers do not reduce wages; everyone gets the same pay and benefits as before.

The 38 participating organizations employ about 2,200 to 2,300 people, O’Connor said.

Not all 38 companies have decided to go public just yet, O’Connor said. There are 20 companies and nonprofit organizations that have decided to disclose their participation in the pilot program. They are:

• advanced VR
• Blue Sky Philanthropies
• CULTIC
• Investment projector
• Fresh ideas in a hurry
• Strategic Communications and Public Relations GillespieHall
• Gliding design
• Health
• DPI Denver
• Starter
• Mental Health Advocacy Services
• Montana Nonprofit Association
• M’tucci Restaurants
• own trail
• Public Policy Lab
• run for something
• Seed and spark
• simPRO
• Association USENIX
• WYNDR

While a four-day week is still rare in the United States, it has grown in popularity in other parts of the world. A study in Iceland involved moving about 1% of the country’s workforce to a 35 or 36 hour week, reports the Washington Post. They found that employees loved the shorter week and productivity stayed the same or improved.

“There’s actually quite a large — and growing — amount of current literature on the four-day work week,” Timothy P. Munyon, associate professor of management at the University of Tennessee, told Nexstar. WATER. “The general consensus is that it improves productivity, reduces burnout and increases respite.”

O’Connor — who works a four-day week, by the way — is confident that participants will see equally positive results from their trials.