Retailers and parcel delivery service companies are leading the way, with one company allowing workers to take second jobs to help make up for lost income.

In a typical four-day workweek, people work 10 hours per day, compared with eight hours daily in the conventional five-day workweek. The new system is aimed at giving more days off to workers who care for children or other family members.

Fast Retailing Co., the operator of the Uniqlo casual clothing store chain, is one of the companies that have adopted a four-day workweek.

The system is used by an increasing number of employees, men and women alike, according to a public relations official.

"We thought it would be used mostly by women taking care of children, but many men are also using it to set aside time for nursing care," the official said.

Sagawa Express Co. has started recruiting midcareer parcel delivery drivers under a four-day workweek in some areas of Japan.

Yahoo Japan Corp. launched a four-day workweek in April, while Yamato Transport Co., the leading door-to-door parcel delivery company under the wing of Yamato Holdings Co., is discussing whether to adopt one.

But as of January 2016, companies that give their employees three or more days off per week accounted for a mere 5.8 pct of all companies in Japan, according to a survey by the Ministry of Health, Labor and Welfare.

Four-day workweeks have not yet received wide support across Japanese business circles.

"It's not suited for workplaces with irregular work shifts," said Tetsuro Tomita, president of East Japan Railway Co.

"Employees (at our company) are already active in taking paid leave. We are not currently considering it (a four-day workweek)," an official of a major securities company said.

Under a four-day workweek system, workers have more days off but face reduced incomes due to falls in overtime.

Sagawa Express estimates that drivers who work in Tokyo under the new system will earn about 270,000 to 360,000 yen per month, including overtime pay and other allowances, lower than 300,000 yen to 430,000 yen for personnel under a five-day workweek.

The company plans to allow drivers who work under the new system to take second jobs, such as part-time jobs in convenience stores, to help cover the drops in income.

At Yahoo Japan, only a few employees work a four-day workweek. "We've just started, so we don't yet know what the challenges are," a spokesman said.

Currently, the four-day workweek system is intended only for employees raising children or providing nursing care, but the company plans to make it available for all employees.

"I want them to have time for themselves outside the office, in order to work more creatively," Yahoo Japan President Kentaro Kawabe said. (Jiji Press)