What the law actually says

This is not legal advice. This page cites verifiable texts and rulings and gives you what you need to read them yourself. A specific situation — a company-level agreement to draft, a pay cut, senior-executive status — calls for a lawyer. Those points are flagged as they come up.

First, a distinction almost everyone misses

Two very different arrangements share the same name, and that is the source of nine misunderstandings out of ten:

• the compressed week — the same number of hours packed into four days instead of five. Each day is longer;
• the shortened week — a genuine reduction in working time, 32 hours instead of 35, for instance.

The distinction is not academic. Out of 150 company agreements recorded in France in 2023, 133 — nearly nine in ten — are plain compressions, with no reduction in hours and no change in pay. Fifteen cut hours without cutting pay; two cut both (Pauline Grimaud, "La semaine de 4 jours", Connaissance de l'emploi no. 199, CEET, September 2024).

An employee who hears "four days" and understands "I will work less" is wrong nine times out of ten.

Is it legal in France?

Yes — and no statute provides for it. A search across the whole body of French law on Légifrance, for "semaine de 4 jours" as well as "semaine de quatre jours", returns no article at all. The arrangement is neither authorised nor forbidden by a dedicated text: it falls under the ordinary law of working time.

Parliament has taken a position on this. National Assembly information report no. 460, tabled on 16 October 2024, states that "the arrangement can be established without difficulty on the basis of the legal rules in force. Legislative intervention therefore does not appear necessary". The rapporteurs go further and describe themselves as "resolutely hostile" to a general statute. So this is not a pending project: it is a deliberate choice.

Do you need a company agreement?

Counter-intuitive but decisive: a plain compression with an unchanged weekly total requires no collective agreement. The articles governing "working-time arrangement" (L. 3121-41 and L. 3121-44 of the labour code) only cover periods longer than a week. Reorganising a week within itself falls under the employer's managerial authority.

Two constraints apply regardless, and they are independent of each other:

1. The works council must be consulted from 11 employees onward, since working time and its arrangement fall within its remit (article L. 2312-8, II, 3°). One nuance: where the project takes the form of a collective agreement, the negotiation replaces the procedure (article L. 2312-14).
2. The employee must consent as soon as the number of working days changes — see below, this is the most widely misunderstood point.

Lawyer recommended to draft a company agreement: the choice of legal instrument, reversibility and voluntary participation are all settled there.

How many hours a day may you work?

This is where the law gets very concrete. Four days must absorb the weekly volume, and the ceilings are these:

What is capped	Ceiling	Text
Length of one day	10 hours	L. 3121-18
Day, under a collective agreement	12 hours maximum	L. 3121-19
Week, absolute ceiling	48 hours	L. 3121-20
Week, average over 12 weeks	44 hours (46 by agreement)	L. 3121-22 and L. 3121-23
Rest between two days	11 consecutive hours	L. 3131-1
Weekly rest	24 hours, added to the 11	L. 3132-1 and L. 3132-2

The arithmetic that decides everything:

• 35 hours over 4 days = 8 h 45 per day. No agreement needed.
• 39 hours over 4 days = 9 h 45 per day. Still within the rules.
• 42 hours over 4 days = 10 h 30 per day. A collective agreement becomes mandatory (L. 3121-19).
• Beyond 12 hours a day: impossible, whatever the agreement says.

A point of vocabulary often reported wrongly: the overtime trigger is weekly, not daily (L. 3121-27). Working 9 hours on a Tuesday creates no overtime as long as the week stays at 35 hours.

And a clarification that saves you from citing an article that does not exist: the famous "35-hour weekly rest" is nowhere written in those words. It is the sum of the 24 hours in article L. 3132-2 and the 11 hours in article L. 3131-1.

Can you lose pay?

No text requires pay to be maintained when working time genuinely falls. Keeping pay unchanged is a company decision — a common one, but a decision.

What protects the employee is that this decision cannot be imposed on them: "an employee's contractual remuneration is an element of the employment contract which cannot be modified, even minimally, without their consent" (Cour de cassation, social chamber, 19 May 1998, no. 96-41.573).

Two further safeguards complete the picture: the minimum wage as an absolute hourly floor, and article L. 3123-5, which requires a part-time employee's pay to be proportionate to that of an equivalent full-time employee — proportionality, not maintenance.

The trap inside the trap: dropping below 35 hours turns the contract into part-time (L. 3123-1), with consequences for social contributions and pensions. The law always compares a volume of hours, never a number of days: an employee on 4 × 8 h 45 remains full-time.

In return, part-time work is better protected on one specific point: the distribution of working time across the days of the week is a mandatory term of the written contract (article L. 3123-6). It is therefore contractual as of right, where it often remains merely indicative for full-timers — the employer can change it only if the contract already sets out the cases and the nature of that change.

Lawyer recommended as soon as a pay cut is contemplated: this is directly litigious ground.

Can an employer impose it? Can an employee demand it?

The dividing line is not the size of the change, but what the contract fixed.

What changes	Legal characterisation	Can the employee refuse?
The spread of hours within the day, hours and pay unchanged	Mere change in working conditions	No — refusal may be misconduct
The number of working days (4 instead of 5, or the reverse)	Modification of the employment contract	Yes, and that refusal is not misconduct

The first line comes from the ruling of 22 February 2000 (no. 97-44.339): a new spread of hours within the day, with identical duration and pay, is only a change in working conditions.

The second comes from a ruling on exactly our subject, going the other way. Three employees had worked four days a week since 1995; the employer demanded a return to five days, then dismissed them for gross misconduct when they refused. The Cour de cassation quashed that: moving from four days to five is a modification of the contract, and refusing a modification of the contract is not misconduct (23 January 2001, no. 98-44.843).

And if the change comes from a collective agreement?

This is the question readers leave with, and it deserves a clear answer. A collective agreement does not automatically override everything in the contract: its clauses apply in principle (article L. 2254-1), but the Cour de cassation has consistently held — since 2001, confirmed again on 17 November 2021 — that "a collective agreement cannot modify, without the employees' consent, the rights they derive from their employment contract".

But since 2017 there is a tool built for exactly this case, and it changes the picture: the collective performance agreement (article L. 2254-2). Its text expressly covers the power to "adjust working time, its organisation and its distribution". The mechanism runs as follows:

• its terms substitute automatically for conflicting contract clauses;
• the employee may refuse, in writing, within one month;
• but the employer then has two months to start a dismissal, on "a specific ground which constitutes a real and serious cause".

In other words: faced with a collective performance agreement, refusal remains a right — it is not misconduct — but it is not without consequence. That is the decisive difference from the 2001 ruling, which concerned a unilateral decision by the employer.

One last point, and it matters: outside a collective performance agreement and outside a multi-week working-time arrangement agreement (L. 3121-44, where the Cour de cassation held on 11 May 2016 that individual consent is not required), we found no ruling deciding the case of an ordinary collective agreement that changes the number of working days. The general principles point towards consent being required, but we do not assert it: the exact characterisation of the agreement changes the answer entirely.

A lawyer is essential here, more than anywhere else on this page. The first thing to establish is the nature of the agreement being invoked against you — ordinary agreement, working-time arrangement agreement, or collective performance agreement. The three do not give the same answer, and the one-month window to refuse a collective performance agreement runs fast.

Symmetrically: no French rule lets an employee demand a move to four days. They can ask; the employer can refuse without giving reasons. That is a sharp difference from Belgium and federal Canada, where a framed right to request exists (see below).

Time-off days, paid leave, public holidays

Paid leave does not change. Entitlement accrues at 2.5 working days per month, capped at 30 working days (L. 3141-3), and the count runs on the working days of the absence period — regardless of the employee's personal rhythm. An employee on four days therefore accrues the same 30 working days as one on five.

RTT days, on the other hand, can disappear. They rest on working-time arrangement beyond the week (L. 3121-44). If the move to four days brings the total to 35 hours or less, their basis vanishes: renegotiation is required.

Public holidays follow two opposite regimes, and this is one of the most expensive things to characterise wrongly. The Cour de cassation held on 18 March 2020 (no. 19-12.702) that where a non-worked public holiday falls on a weekly rest day it gives rise to no compensation — but where it falls on a rest day granted under a working-time arrangement agreement, the employer must compensate. Everything therefore depends on how the non-worked day is characterised.

Lawyer recommended to characterise that day within a given scheme: the financial stake is immediate.

Day-rate executives, public service, senior executives

Day-rate arrangements. Available to autonomous executives (L. 3121-58), capped at 218 days a year (L. 3121-64 — not L. 3121-58, a frequent error). The day rate sets aside hourly counting, but not daily and weekly rest. The four-day week has no distinct legal expression there: it takes the form of extra rest days.

Public service. Decree no. 2000-815 of 25 August 2000 (State) and decree no. 2001-623 of 12 July 2001 (local authorities) set 1,607 annual hours and allow work cycles to be defined — but through an act adopted after an opinion from the competent body, never by unilateral decision. Neither text mentions the four-day week; it goes through the cycle mechanism.

Senior executives. Article L. 3111-2 excludes them from working-time and rest rules — but not from paid leave. For them the four-day week has literally no legal meaning: no maximum duration is enforceable against them. The three criteria for that status are cumulative and strictly reviewed.

Lawyer recommended: a badly assigned senior-executive status exposes the employer to retroactive overtime claims.

Where does French law stand?

Nowhere, and not by accident.

Text	Status
Senate bill no. 482 (March 2023)	Lapsed
National Assembly bill no. 2065, for volunteers (January 2024)	Report tabled, never scheduled for debate; lapsed with the June 2024 dissolution
National Assembly information report no. 460 (October 2024)	Published; no bill followed from it
Citizens' petition i-3637	Closed in April 2026: 125 signatures out of the 10,000 required

Two French experiments have produced public figures, and they say opposite things:

• the Lyon metropolitan authority ran an experiment from September 2023 on 315 staff, with a favourable assessment — 93 % of respondents wanted it made permanent — and voted to extend it to 5,500 eligible staff by a decision of 24 June 2024;
• Urssaf Picardie, heard by the parliamentary mission, had 200 eligible employees and three quarters expressing interest at the outset. Three signed up. All of them without dependent children.

That gap between stated support and actual take-up is the most consistent fact in the whole file, and the explanation looks material rather than ideological: school and childcare hours are built on five days.

And elsewhere?

Belgium — a right to ask, not a right to obtain

The Act of 3 October 2022 inserted an article 20bis/1 into the Act of 16 March 1971. Its wording is precise: work rules may allow a full-time worker to raise their daily limit to 9 h 30 if they perform their work over four days. That is a compression, not a reduction: the shorthand "four days paid as five" corresponds to nothing in the text.

The worker applies in writing; the employer must accept for the arrangement to exist, and a refusal must be reasoned in writing within a month — with the law placing no limit on the grounds. The employee is protected against dismissal linked to the request.

Actual take-up has stayed marginal — that is the finding that recurs in French parliamentary work as in the Belgian press. The precise rates in circulation ("one worker in 200", "0.8%") could not be traced back to a primary source, so we do not repeat them.

Switzerland — lawful, but with no right to claim it

No dedicated federal statute. The Labour Act caps 45 or 50 hours per week depending on the sector, with 11 hours of daily rest: it limits hours, never days. A four-day week is therefore lawful with no particular procedure — but no individual right allows anyone to request it. Federal parliamentary initiatives have all been rejected or dropped. A trial framed by the Bern University of Applied Sciences began in March 2024; its results are not published — the report is announced for November 2026.

Luxembourg — nothing specific

No dedicated legal arrangement was found. The general framework sets 8 hours a day and 40 hours a week as ordinary, with ceilings of 10 and 48 hours, 11 hours of daily rest and 44 hours of weekly rest — appreciably more protective than the Belgian regime. No Luxembourg pilot scheme was identified.

Spain — a subsidy, not a law

No statute imposes or frames the four-day week. The public scheme rests on an order of 9 December 2022 issued by the Ministry of Industry — not the Ministry of Labour: a subsidy covering up to 90 % of the budget of industrial SMEs cutting their working day by at least 10 %, over a project of at least 24 months, for a declared envelope of 9.65 million euros.

What the official subsidy register lets you verify is soberer than what you read: four subsidised companies as of mid-September 2024, for 537,423 euros — about 5.6 % of the available credit. No evaluation report has been published, and the minimum project duration did not yet require one. Any Spanish outcome figure circulating today therefore has no primary source.

United Kingdom — the best-documented trial, with no law at all

The 2022 pilot covered 61 companies and about 2,900 employees (the widely repeated figure of 70 companies is wrong). At the end, 56 of the 61 companies, or 92 %, continued.

On revenue, two numbers circulate and only one describes the trial: +1.4 % from the start of the experiment to its end. The famous "+35 %" compares with an earlier six-month period, on a different sample.

The spectacular falls in absenteeism (−65 %) and resignations (−57 %) are real in the data, but the report itself states that it cannot assert their statistical significance — a caveat systematically dropped when the figures are repeated.

On the legal side: no statute, no bill. A search of the official UK Parliament database for "four day week" and its variants returns no text tabled.

Quebec and federal Canada — two regimes with different constraints

Neither Quebec's Act respecting labour standards nor the Canada Labour Code mentions the four-day week.

In Quebec, the standard week is 40 hours (section 52), and the threshold is weekly: a compression into 4 × 10 hours therefore triggers no overtime. Weekly rest is 32 consecutive hours (section 78).

At federal level the difference is structural: there is a daily ceiling of 8 hours on top of the weekly one (section 169(1)). On the other hand, after six months of service an employee has a right to request a change to their schedule, with an answer within 30 days and enumerated grounds for refusal (section 177.1) — a right to request, not to obtain.

And the figures you read everywhere?

They too call for caution: of twenty claims we traced back to their primary source, only four are faithful. The detail, source by source, is in the figures in circulation.

What this page does not say

Several official sources were unreachable during the verification of 30 August 2026: the assessment of the State civil-service experiment after 2024, the Belgian evaluation provided for by the 2022 Act, Luxembourg statistical data, and the most recent Spanish parliamentary status. We prefer to say so rather than paper over the gaps with smooth phrasing. They will be filled when the sources reopen.