How to Implement a Four-Day Work Week: Models, Pilot and Legal Steps

How to implement a four-day work week: choose one model (reduced hours at full pay, compressed hours, a 9-day fortnight or staggered days off), measure a baseline, run a 3–6 month pilot with clear KPIs and customer coverage rules, check working-time law and contracts, and only then decide whether to make it permanent. The hard part is not the idea but the rota, the contracts and the pay rules.

This guide is the practical playbook. It compares the models in a table, sets out a pilot plan, lists the legal and contract points to check in the EU, Belgium, Spain, the UK and the US, and explains what happens to pay, holiday and overtime. It ends with TalentUp job ad data on where the 4-day week is hardest to offer. For the trial results and the research behind the policy, read our companion article on 4-day week results and evidence.

Step 1: Choose Your Four-Day Week Model

“Four-day week” covers very different arrangements. Decide which one you mean before you talk to employees, because the cost, the contract change and the legal checks depend on it.

Two questions decide most cases. Can the work be measured by output rather than presence? If yes, 100-80-100 is realistic. Does the business need continuous cover? If yes, you will need staggered days or a compressed rota, whichever model you pick.

Step 2: Run a 3–6 Month Pilot

A pilot turns an opinion into data. Keep it time-limited, reversible and documented.

1. Define the scope. Start with one or two teams whose work you can measure, plus at least one team that will stay on five days for comparison.
2. Measure a baseline. Collect 3–6 months of data before the pilot: output, quality, response times, sick days, overtime, turnover and an employee survey.
3. Remove work, not just a day. Audit meetings, approvals and reporting. Most successful pilots cut meeting time and low-value tasks before the first day off.
4. Design the coverage rota. Decide who covers which day, how on-call works and what the escalation path is. Tell key clients in advance.
5. Set the rules. Write down how holiday, public holidays, sick days, overtime and “emergency” Fridays work during the pilot.
6. Agree the exit. State that the pilot can be stopped or adjusted, and give individuals a way to opt out (for example, if longer days don’t fit their caring duties).
7. Review at mid-point and end. Compare KPIs with the baseline and the control team, then decide: keep, adjust or stop.

Pilot results elsewhere are encouraging: in the 2022 UK pilot, 56 of 61 organisations kept the 4-day week after six months. The evidence and its limits are covered in our 4-day week results article.

Step 3: Check the Legal and Contract Points

There is no single “4-day week law”. You have to fit your model into working-time rules, contracts and, where they exist, collective agreements. Always check national law and get local legal advice before rollout.

EU Working Time Directive

Directive 2003/88/EC sets the floor in every EU country:

• 48 hours average per week, including overtime, over a reference period of up to four months.
• 11 consecutive hours of daily rest and a weekly rest period of 24 hours plus the 11 hours of daily rest.
• Four weeks of paid annual leave.
• An average of 8 hours per 24 hours for night workers.

A compressed 4 × 10 schedule fits within these limits, but national laws often add daily caps. In Germany, the Arbeitszeitgesetz §3 allows up to 10 hours a day only if the average stays at 8 hours per working day over six months or 24 weeks. In Spain, ordinary working time cannot exceed 9 hours a day unless a collective agreement or an agreement with workers’ representatives sets a different distribution, with at least 12 hours of rest between workdays (Estatuto de los Trabajadores, art. 34).

Contracts and Collective Agreements

• Contract variation. Changing working days, hours or pay is a change to terms and conditions. Agree it in writing; for a pilot, use a temporary written variation with an end date. In Spain, for example, a full-time contract can only become part-time with the employee’s consent (Estatuto de los Trabajadores, art. 12.4), and collective changes to working time follow the consultation procedure in art. 41.
• Collective agreements and works councils. Many sector agreements regulate the distribution of hours. Where there is a works council or union delegation, involve it early: in many countries consultation is required before changing working time.
• Working-time records. In Spain, employers must keep a daily record of working hours for every worker, including start and end times (Real Decreto-ley 8/2019, art. 34.9 of the Estatuto). The government has proposed rules to make the record digital; check their status before you choose a tool.

Country Rules Worth Knowing

• Belgium: since the Labour Deal (law of 3 October 2022), full-time employees can request in writing to work their full-time hours over four days, for renewable periods of up to six months. Days can be up to 9.5 hours where the work rules allow it, or 10 hours for a 40-hour week if a collective agreement provides for it. A refusal must be justified in writing within one month, and voluntary overtime on the fifth day is not allowed.
• United Kingdom: employees have a day-one right to request flexible working, including compressed hours, and can make two requests in 12 months; the employer must decide within two months (GOV.UK).
• United States: under federal law overtime is calculated per workweek over 40 hours, so a 4 × 10 week does not trigger overtime by itself. Some states differ: California requires daily overtime after 8 hours unless an alternative workweek schedule is adopted by a secret-ballot vote of the affected employees (California DIR).

Step 4: Pay, Holiday and Overtime Rules

Most implementation problems surface in payroll. Settle these points before the pilot starts:

• Keeping pay at 100%. In the 100-80-100 model salaries stay the same, which means the effective hourly rate rises by 25%. For hourly-paid staff you must raise the hourly rate, or their pay falls with their hours.
• Pro-rata holiday. Express leave in weeks, then convert to days. The EU minimum of four weeks is 20 days on a five-day week and 16 days on a four-day week; in the UK, the statutory 5.6 weeks is 28 days on five days and 22.4 days on four. See our guides to paid leave and vacation days in Europe.
• Public holidays. Decide what happens when a public holiday falls on someone’s day off. Common options are a day in lieu for everyone or pro-rating public holidays into the leave allowance, so Monday-off and Friday-off employees are treated the same.
• Overtime. Define the overtime threshold for the new pattern (weekly or daily, depending on the law and agreements). Track work on the off day: unpaid “quick checks” on Fridays undermine the model and can breach working-time rules.
• Benefits tied to days worked. Meal vouchers, commuting allowances and shift premiums are often paid per day. Decide whether they stay at five days or move to four.
• Pay transparency. Where the EU Pay Transparency Directive (2023/970) applies through national law once transposed, pay levels include gross hourly pay. If one group gets 100% pay for 32 hours and another works 40 hours for similar pay, the hourly difference must rest on objective, gender-neutral criteria. Our pay equity audit guide explains how to check it.

Where a Four-Day Week Is Hard: TalentUp Data

Source: TalentUp job postings database, January–September 2026, about 16 million job ads with a description.

Job ads show where employers actually offer a 4-day week. Between January and September 2026, 13,280 ads out of about 16 million with a description mentioned a 4-day week in one of nine languages: 8.3 in every 10,000. The sector pattern is not what the pilots suggest.

• Shift sectors offer compressed rotas, not shorter weeks. In a sample of 3,224 ads, 11.6% said which model they offered. Among production, operations, transport and repair ads that did, 68 of 81 described compressed hours (such as 4 × 10 hours); in healthcare 37 of 51. In IT, 23 of 31 described reduced hours such as 32 hours or full pay.
• Healthcare’s high rate is mostly clinics, not wards. Many healthcare mentions are US physician, dental and veterinary roles with outpatient schedules, not hospital shifts.
• Customer-facing and cleaning roles lag. Hospitality (5.5), customer support (7.1) and cleaning (3.2) are below average, consistent with the coverage problem in these jobs.
• Mid-sized companies offer it most. Ads from companies with 51–500 employees mention it 11–18 times per 10,000; companies with more than 500 employees 2–9 times. Very small firms (1–20 employees) sit near the average at about 9–10.

How the 4-day week varies by country and year, and how it affects advertised salaries, is covered in our 4-day week results article.

Alternatives for Shift Work, Client-Facing Roles and Small Teams

If a full 4-day week does not fit, you can still offer part of the benefit:

• Staggered or rotating days off. Split the team into two groups with Monday or Friday off, so cover stays at five days.
• Compressed rotas. 4 × 10 or 3 × 12 shifts are already common in healthcare, manufacturing and logistics. Check daily limits, rest periods and fatigue risk.
• 9-day fortnight. Half the time off of a weekly day off, but much easier to cover.
• Shorter Fridays or summer hours. A reduced day during low-demand months is cheap to test.
• Annualised hours. Fewer days in quiet seasons and more in busy ones, where the law and agreements allow.
• Voluntary 4-day part-time. For small teams that can’t afford 100-80-100, a protected right to request 80% hours is better than nothing.

Laurent de la Clergerie, founder and president of Groupe LDLC, moved all of the French electronics retailer’s employees to a 32-hour, four-day week without a pay cut in January 2021, and suggests a halfway model for companies that think it can’t work for them.

For broader options, see our guide to flexible working policies and what HR can offer besides salary.

Spain: What Companies Have Tried

Spain shows both sides of the debate, and why the pay deal decides the outcome.

• Desigual (2021). About 500 staff at the Barcelona headquarters voted on a 4-day week of 34 hours instead of 39.5, with one remote day. Hours fell by 13% and pay by 6.5%, with the company covering the other half. 86% voted in favour. It applied at the headquarters, not in the stores, which illustrates how hard retail is. The union UGT criticised the process, arguing that a formal consultation was required for a collective change in working conditions (Ara).
• Telefónica (2021–2022). The company offered a voluntary week of 32 hours over four days, instead of 37.5, with a pay cut proportional to the hours removed and the company covering 20% of the loss. About 150 employees joined the 2021 pilot before it was opened to around 18,000 staff in 2022 (CIO España).
• Government pilot for industrial SMEs. The Ministry of Industry opened a call of €9.65 million for SMEs that cut working time without cutting pay for at least two years. Only 41 companies applied, and in September 2024 five received about €530,000 (La Moncloa; Ministry of Industry).

The lesson travels: when employees pay for the day off with a large salary cut, take-up stays low. When the employer shares the cost or finds the productivity to fund it, more people take it.

How to Communicate the Change

• Explain the why and the model. Say exactly which model you are testing, for whom and for how long. Avoid promising “a 4-day week” if you mean 4 × 10 hours.
• Be clear about pay. State in writing whether pay, holiday, benefits and overtime change.
• Explain who is excluded and why. If some roles can’t take part, say why and what they get instead. Unexplained exclusions damage trust more than no pilot at all.
• Tell clients and suppliers. Share coverage hours and contacts for the off day before the pilot starts.
• Publish the results. Share the KPI review with employees, including what didn’t work.
• Use it in recruitment carefully. If you keep it, describe the real model in your job ads; candidates read “4-day week” as full pay. See our guide to what candidates look for in employers.

Sources

• TalentUp. Job postings database, January–September 2026: about 15.95 million ads with a description, 13,280 mentioning a 4-day week, and a random sample of 3,224 ads for model classification (see methodology above).
• European Union. Directive 2003/88/EC concerning certain aspects of the organisation of working time. EUR-Lex.
• European Union. Council Directive 97/81/EC on part-time work. EUR-Lex.
• European Union. Directive (EU) 2023/970 on pay transparency. EUR-Lex.
• Germany. Arbeitszeitgesetz, §3 Arbeitszeit der Arbeitnehmer. Gesetze im Internet.
• Spain. Estatuto de los Trabajadores (Real Decreto Legislativo 2/2015), art. 34 and Real Decreto-ley 8/2019. BOE.
• Spain. La Moncloa, press release on applications to the 4-day week pilot programme (2023) and Ministry of Industry, press release on the pilot programme awards (20 September 2024).
• Belgium. L&E Global, Labour Deal 2022: 4 day work week and alternating work week (2022).
• United Kingdom. Flexible working and Holiday entitlement. GOV.UK.
• United States. California Department of Industrial Relations, Overtime FAQ, including alternative workweek schedules.
• Ara. The dilemma of Desigual staff: work five days or work four and get paid less (October 2021).
• CIO España. La jornada laboral de cuatro días se consolida en Telefónica (June 2022).
• Autonomy. The results are in: the UK’s four-day week pilot (2023).