There are different interpretations of the four-day week and how it can be applied, but these three approaches are considered to be the most popular.

This article is part two in our series on the four-day week. In the series, you'll learn what the four-day week is, the main motivations for implementing it and how to measure and track its success. You can see other articles in the series at the bottom of this page.

Sometimes called the compressed model, this is the interpretation of the four-day week that is currently making headlines in Belgium after its government announced in February that any employee could ask to work their allotted 38 hours across just four days.

One potentially appealing aspect of this option to employers is that they are not giving their employees anything "for free". In our February 2022 poll of 1,000 UK SMEs, this model proved to be the most popular choice (39 per cent) when respondents were asked what kind of four-day week they would consider implementing or had already implemented.

There are variations on this theme, such as the 5-4-9 work schedule, in which employees work nine hours per day for five days, followed by nine hours for four days in week two.

A second way for employees to work the equivalent of four days is to work five shorter days – a move that frees them up for things like school runs, medical appointments and so on. The downside of this model is that it still requires a daily commitment from people and doesn't reduce their weekly commuting time. Salaries can either be maintained or cut to reflect the new hours, depending on company policy.

Though one way of doing this would be to cut wages by 20 per cent to reflect the reduction in hours, relatively few businesses seem to be pursuing this route. What is gathering momentum instead is sometimes called the 100-80-100 approach, which is based around the idea of staff doing 100 per cent of the work in 80 per cent of the time at 100 per cent of their pay.

This version is attracting the most media attention – not least because well-known companies such as Microsoft, Unilever and Wanderlust have all either trialled or implemented it. Interestingly, this model was the third most popular option (30 per cent) in the Be the Business poll, just behind a simple reduction in hours for less pay.

This guide will mainly focus on option three, because this is where there is most pilot study-based analysis being carried out. It’s also of particular interest to Be the Business because it promotes the idea of greater productivity – getting more done in fewer hours – alongside improved staff wellbeing and happiness.

A more productive work week

One of the businesses signed up to take part in a UK pilot is MBL Seminars, whose chairman Morgan Rigby said that the chance to be part of something new and exciting is a significant attraction.

"If we do make a success of it, it would be something that the team can feel proud of – that they are part of something even wider than our own business," he added.

Data from earlier trials suggests a more productive four-day working week is within our grasp. Between 2015 and 2019, the country of Iceland ran two large-scale trials of a reduced working week (35-36 hours) with no reduction in pay. These were considered to be an "overwhelming success", with productivity remaining the same or improving in most cases.

In 2018, a New Zealand company named Perpetual Guardian trialled a four-day work week and reported a 20 per cent increase in productivity and happier staff. The country's prime minister Jacinda Ardern went on to encourage other businesses to try it.

Throughout our exploration of the four-day week we will hear from several UK small and medium-sized businesses that have already implemented a four-day week, or are about to start one, to discover what is driving the change and how this all fits into the new, post-coronavirus business landscape.

You can revisit the previous article in our series below:

• An introduction to the four-day week

Read the next article in our four-day week series here:

• The motivation for UK businesses