The idea behind a four-day work week is that instead of an employee working five days of the week, he simply condenses his hours into four working days. This means there is no change to the number of hours the worker clocks each week, no change to his salary, and no change to the number of employees needed by the company to achieve optimum productivity. This approach to business is increasing in popularity within some industries in the United States because of its cost-reducing benefits. However it does come with disadvantages, which also need consideration.

Advantage: Environmental Benefits

Having a four-day work week can be greatly beneficial to the environment. This is because it means one day less is spent commuting to and from work and consuming energy in the office, ultimately resulting in a lowering of greenhouse gas emissions. According to "Time" magazine, the state of Utah found that it had a 13 percent reduction in energy use, and workers saved around $6 million in fuel costs, when it commissioned the trial for businesses in the state to try a four-day work week in 2009. According to findings, the initiative would reduce the state's greenhouse gas emissions by more than 12,000 metric tons a year.

Advantage: Reduction in Costs

A four-day week would save both the company and the employee money, according to a report by David Muir on ABC World News. For employees, a day less at work would mean less spent on fuel to commute and, for parents, less spent on childcare. For the employers, a day less of work would reduce operational costs like security and maintenance costs, and would ultimately lower utility bills.

Advantage: Increased Productivity

Having a four-day week could boost productivity because of the positive effect that an extra day off could have on employees' morale. It means more time with family and a better work-life balance, which in turn can improve workers' attitudes towards their job because they are less tired and resentful of the time their career takes up. This can result in a reduced amount of worker absenteeism, which will in turn benefit productivity levels in the long-run, reports "Time" magazine.

Advantage: Customer Satisfaction

Another benefit to a four-day week is that from Monday through Thursday, businesses are likely to be open earlier and to remain open later, making them more available for working customers because of longer business hours. Standard business hours of 9 to 5 can often mean that customers have to miss work or other commitments in order to access a business, so extended working hours four days a week will reduce this problem.

Disadvantage: Health and Safety

A four-day week means that the working day must be extended to up to 10 hours in order to compensate for the time lost by the extra day off. According to a "Forbes" article on the topic, this could impact worker safety, depending on the type of industry, because longer hours could result in worker fatigue, which in turn could cause the amount of work-related accidents to increase. This would be a bigger risk for heavy machinery operators than for sedentary office workers.

Disadvantage: Risk to Customer Sales and Confidence

One less business day a week could negatively affect sales and customer confidence, depending on the type of industry. Customers might resent the fact that they can no longer access the business on a chosen day, which could encourage them to use a competitor business instead.

Disadvantage: Family Schedules

Having a four-day working week could put strain on employees who have children. For example, organizing childcare for the longer working hours of a 10-hour day could prove difficult, as could leaving the house very early particularly if workers have young children. This change in routine could put stress on employees and their families, which in turn could actually negatively impact the morale of a workforce or create problems with worker punctuality.