Can working hours differ between busy and quiet months? Choosing between variable working hours and flexitime

Bottom line first: A company whose busy and quiet seasons differ sharply can redistribute working hours over a month or a year. It is not a scheme that makes overtime pay disappear. Four systems are available, and the procedure and the ceilings differ for each.

The principle in the Labor Standards Act (労働基準法) is eight hours a day and 40 hours a week (Article 32). Variable working hour systems and flexitime allow that frame to be met on average over a set period, so nine hours in a busy week and seven hours in a quiet week can be scheduled in advance.

The clearest fork is the procedure. The one-month system can be introduced by a labour-management agreement or by the rules of employment; the one-year system requires an agreement. Flexitime needs no filing when the settlement period is one month or less, and filing becomes necessary once it exceeds one month.

Which system suits a particular company, and whether the wording of an agreement or of the rules of employment matches how that company actually works, cannot be settled by an article. What follows is the shape of each scheme and the points that are most often missed.

What does a variable working hour system actually change?

It changes how scheduled working hours are laid out, not the total.

Article 32 of the Labor Standards Act provides that an employer shall not have a worker work more than 40 hours per week excluding rest periods, nor more than eight hours a day for each day of the week. A variable working hour system is an exception: if the average weekly working hours over a set period stay within that frame, work exceeding it is permitted in a specified week or on a specified day.

In other words, it is not a scheme that erases 80 hours of overtime; it is a scheme that lets a nine-hour day and a seven-hour day be fixed in advance. Introducing it on the opposite understanding is how unpaid premium wages accumulate.

How do the one-month, one-year, one-week and flexitime systems differ?

They differ in how they are introduced and whether a filing is required.

System	Basis	How it is introduced	Period	Filing with the Labour Standards Inspection Office
One-month variable working hours	Article 32-2	Labour-management agreement or rules of employment or equivalent	Up to one month	Required where fixed by agreement (Form 3-2)
One-year variable working hours	Article 32-4	Labour-management agreement only	Over one month, up to one year	Required (Form 4)
One-week non-fixed variable working hours	Article 32-5	Labour-management agreement	One week	Required (Form 5)
Flexitime	Article 32-3	Provision in the rules of employment or equivalent plus a labour-management agreement	Settlement period up to three months	Required only where the settlement period exceeds one month (Form 3-3)

Article 32-5 alone is limited by sector and size. It covers retail, inns, restaurants and eating establishments with fewer than 30 workers ordinarily employed (Ordinance for Enforcement of the Labor Standards Act, Article 12-5, paragraphs 1 and 2). Up to 10 hours a day is permitted, and the working hours for each day of that week must be notified to the worker in writing at least before that week begins (paragraph 3).

For every system, the first day of the period must be made clear in the rules of employment or equivalent or in the agreement (Article 12-2, paragraph 1 of the same Ordinance). This is often missing in practice.

Can the one-month system be introduced through the rules of employment alone?

It can. Article 32-2, paragraph 1 says "by a written agreement or by the rules of employment or the equivalent thereof". Of the four systems, this is the only one that can be introduced without an agreement.

Whether a filing is needed depends on which route was taken. What Article 32-2, paragraph 2 requires to be filed is "the agreement referred to in the preceding paragraph". Where the rules of employment are used, a workplace ordinarily employing 10 or more workers files the rules themselves (Article 89). Creating or amending the rules requires hearing the opinion of the majority representative and attaching the written opinion (Article 90).

Where an agreement is used, it must state a period of validity (Ordinance, Article 12-2-2, paragraph 1). No period of validity is required where the rules of employment are used. That is the practical basis for choosing: the rules of employment for a long-term arrangement, an agreement where the company wants to test it for a fixed term.

The rules of employment themselves are covered in How many employees make rules of employment mandatory.

What ceilings apply to the one-year system?

This system carries the most ceilings, and they usually decide whether it can be used. The agreement must set the scope of covered workers, the target period, the specified period, the working days and the working hours for each working day within the target period, and the period of validity (Article 32-4, paragraph 1; Ordinance, Article 12-4, paragraph 1).

Item	Limit	Basis
Target period	Over one month, up to one year	Article 32-4, paragraph 1, item 2
Working hours per day	10 hours	Ordinance, Article 12-4, paragraph 4
Working hours per week	52 hours	Same
Working days (target period over three months)	280 days per year	Same Article, paragraph 3
Consecutive working days	6 days	Same Article, paragraph 5
Consecutive working days in a specified period	A number that secures one day off per week	Same

Where the target period exceeds three months, two further conditions apply: the number of consecutive weeks with working hours over 48 must be three or fewer, and within each three-month block counted from the first day, the number of weeks beginning with working hours over 48 must be three or fewer (paragraph 4, items 1 and 2).

The 44-hour special measure cannot be used with this system. Workplaces in commerce, film and theatre (excluding film production), health and hygiene, and hospitality and entertainment with fewer than 10 workers ordinarily employed may in principle work up to 44 hours a week (Ordinance, Article 25-2, paragraph 1). But that Article extends 44 hours to variable working hour systems only in paragraph 2 (one month or less) and paragraph 3 (flexitime with a settlement period of one month or less); Article 32-4 is not included. Choosing the one-year system returns the workplace to 40 hours.

When does flexitime require a filing?

Only where the settlement period exceeds one month. Article 32-3, paragraph 4 applies Article 32-2, paragraph 2 mutatis mutandis but adds: "provided, however, that this shall not apply where the settlement period is one month or less". The Ministry of Health, Labour and Welfare guide likewise states that no filing is required where the settlement period is one month or less.

Two things are needed. First, a provision in the rules of employment or equivalent leaving the starting and finishing times to the decision of the worker. Second, an agreement setting the following (Article 32-3, paragraph 1; Ordinance, Article 12-3, paragraph 1):

1. The scope of covered workers
2. The settlement period (up to three months)
3. Total working hours in the settlement period
4. Standard daily working hours
5. Where core time is set, its start and finish
6. Where flexible time is restricted, its start and finish
7. Where the settlement period exceeds one month, the period of validity of the agreement

Where the settlement period exceeds one month, averaging 40 hours a week over the whole period is not enough. Each one-month block counted from the first day must also average no more than 50 hours a week (Article 32-3, paragraph 2). The extension of the settlement period from one month to three months came with the work style reform; the Ministry guide dates it to April 2019.

Does introducing these systems remove overtime pay?

It does not. What changes is how the threshold for overtime is counted.

Under a variable working hour system, hours worked beyond the scheduled hours fixed in advance are overtime. Under flexitime, because daily hours are left to the worker, overtime is judged by reference to the settlement period (Ministry guide). Either way, premium wages under Article 37 apply: at least 25 per cent (at least 50 per cent for the portion exceeding 60 hours in a month) and at least 25 per cent for late-night work.

Having workers work overtime at all requires a separate Article 36 agreement. See Overtime limits are set by the Article 36 agreement. Counting in workplaces with night duty is covered separately in Night shifts and on-call duty at a group home.

May the schedule be changed after introduction?

Under the one-year system, in principle no. Fixing the working days and the working hours for each working day in the agreement is a requirement (Article 32-4, paragraph 1, item 4). Deciding later leaves room for a finding that the requirements were never met.

Where the target period is divided into blocks of one month or more, there is a route. For each block other than the first, only the number of working days and total working hours need be set in the agreement; then, at least 30 days before the first day of each block, the working days and the hours for each working day are set in writing with the consent of the majority representative (Article 32-4, paragraph 2; Ordinance, Article 12-4, paragraph 2).

The one-month system likewise does not mean a pre-fixed roster can be moved at the company's convenience. If changes are foreseeable, the requirements and procedure for changing them belong in the rules of employment or the agreement.

How is pay settled for someone who joins or leaves mid-period?

The one-year system has a settlement rule. Where a worker has worked for a period shorter than the target period, and the average weekly hours over that shorter period exceed 40, premium wages must be paid under Article 37 for the excess (excluding hours extended under Article 33 or Article 36, paragraph 1, and holiday work) — Article 32-4-2.

A calculation arises every time someone joins or leaves during the year. In workplaces with high turnover, whether that calculation can be sustained is the practical test of whether the one-year system is the right choice.

Can these systems be applied as they are to expectant mothers and workers with childcare duties?

Not always. Where an expectant or nursing mother so requests, the employer shall not have her work more than 40 hours a week or eight hours a day, notwithstanding Article 32-2, paragraph 1, Article 32-4, paragraph 1 and Article 32-5, paragraph 1 (Article 66, paragraph 1). Flexitime (Article 32-3) is not in that list.

Consideration for workers with childcare or nursing duties is also prescribed. Where workers work under Article 32-2, Article 32-4 or Article 32-5, the employer must give consideration so that those raising children, caring for the elderly, undergoing vocational training or education, and others requiring special consideration can secure the time they need (Ordinance, Article 12-6).

Deciding in advance how such a request will be handled is the practical step. Measures on the childcare and nursing care leave side are set out in What changed in the 2025 amendment to the Child Care and Family Care Leave Act.

Can anyone be the counterparty to a labour-management agreement?

No. Where there is no union organised by a majority of workers, a majority representative is selected, and the requirements are prescribed (Ordinance, Article 6-2, paragraph 1):

1. Not a person in a supervisory or managerial position under Article 41, item 2
2. A person selected through a procedure such as a vote or a show of hands, conducted on the clear basis that the purpose is to select the person who will conclude the agreement, and not selected on the basis of the employer's intention

A person nominated by the company, or the head of a social club appointed automatically, does not meet the second requirement, and the validity of the agreement itself comes into question. The employer must not treat a worker disadvantageously for being, or seeking to become, a majority representative or for acting properly as one (paragraph 3), and must give the consideration necessary for the representative to carry out the related work smoothly (paragraph 4).

Concluded agreements must be made known to workers. The agreements under Article 32-2, paragraph 1, Article 32-3, paragraph 1, Article 32-4, paragraph 1 and Article 32-5, paragraph 1 must be posted or kept in a conspicuous place in each workplace, delivered in writing, or otherwise made known (Article 106, paragraph 1).

What can 四葉社会保険労務士事務所 do?

What this office takes on is organising the material for the choice, and lining up the documents with the actual operation.

• Organising the material for comparing which system fits the shape of the company's peaks and troughs
• Preparing labour-management agreements and filing them with the competent Labour Standards Inspection Office
• Amending the rules of employment and wage regulations (starting and finishing times, the first day of the period, the procedure for changes, how days off are set)
• Designing the procedure for selecting the majority representative, and supporting the selection
• Reworking the premium wage calculation and the attendance cut-off after introduction
• Organising how requests from expectant mothers and workers with childcare or nursing duties will be handled

The Labor Standards Act is listed in item 1 of Appended Table 1 of the Certified Social Insurance and Labour Consultant Act (社会保険労務士法); preparing applications and notifications under it falls under Article 2, paragraph 1, item 1, and acting on the filing procedure under item 1-2. Advice and guidance on labour management falls under item 3. The fee schedule of this office shows support for the selection of a workers' representative as free of charge.

The following are not handled here.

• Negotiation or litigation once unpaid premium wages become contested → we refer you to a lawyer (Bengoshi)
• Tax treatment of wages and year-end adjustment → we connect you with a tax accountant (Zeirishi)
• Company registration procedures → we connect you with a judicial scrivener (Shiho Shoshi)
• Preparing licence and permit applications → 四葉行政書士事務所 accepts this as a separate business entity
• Leases of premises or company housing → 四葉不動産株式会社 accepts this as a separate business entity

四葉不動産株式会社, 四葉行政書士事務所 and 四葉社会保険労務士事務所 each accept work as an independent business entity, under a separate contract. Where another professional is introduced, you contract with them directly, and this office receives no referral fee.

Consultations are free of charge. Fees are set out in the fee schedule; see also our services and how a consultation proceeds.

Frequently asked questions

Q. Is the one-month variable working hour system invalid if no filing was made?
A. It depends on how it was introduced. What Article 32-2, paragraph 2 of the Labor Standards Act requires to be filed is the labour-management agreement. Where the system was introduced through the rules of employment or the equivalent, it is not covered by that filing duty; a workplace ordinarily employing 10 or more workers files the rules of employment instead (Article 89). This office does not reach a conclusion on the effect in any individual case where no filing was made.

Q. Our workplace may work up to 44 hours a week. Can we also use the one-year system?
A. The system itself is available, but the 44-hour frame is not. Article 25-2 of the Ordinance for Enforcement of the Labor Standards Act extends the 44-hour special measure in paragraph 1 (the general rule), paragraph 2 (variable working hours of one month or less) and paragraph 3 (flexitime with a settlement period of one month or less); Article 32-4 of the Act is not covered. Article 32-4, paragraph 1 itself says "within the limit of an average of no more than 40 hours per week".

Q. Can flexitime be run without core time?
A. It can. Article 12-3, paragraph 1 of the Ordinance requires the start and finish of core time to be set in the agreement only "where it is established", so having core time at all is not mandatory. Restricting flexible time is likewise optional. The items that must be set in the agreement — the scope of covered workers, the settlement period, total working hours in the settlement period and standard daily working hours — cannot be omitted.

Q. Under the one-year system, what if we need more working days because of a rush?
A. Adding working days after the agreement has fixed them runs directly against the requirements. Where the target period is divided into blocks of one month or more, there is a route for each block other than the first: at least 30 days before its first day, set the working days and the hours for each working day in writing with the consent of the majority representative (Article 32-4, paragraph 2). Work needed outside that route is treated as overtime or holiday work within the Article 36 agreement, with premium wages paid.

Basis for this article

• Labor Standards Act (労働基準法, Act No. 49 of 1947) Article 32 — not more than 40 hours a week excluding rest periods, and not more than eight hours a day for each day of the week
• Same Act, Article 32-2, paragraph 1 — "by a written agreement ... or by the rules of employment or the equivalent thereof", where the average weekly hours over a fixed period of up to one month do not exceed the hours in Article 32, paragraph 1
• Same Act, Article 32-2, paragraph 2 — the employer must file "the agreement referred to in the preceding paragraph" with the administrative agency
• Same Act, Article 32-3, paragraph 1 — items 1 to 4, including the settlement period limited to three months and the total working hours in the settlement period
• Same Act, Article 32-3, paragraph 2 — where the settlement period exceeds one month, each one-month block from the first day must average no more than 50 hours a week
• Same Act, Article 32-3, paragraph 4, proviso — "provided, however, that this shall not apply where the settlement period is one month or less"
• Same Act, Article 32-4, paragraphs 1 and 2, and Article 32-4-2 — the one-year system, the 30-day advance setting with the consent of the majority representative, and premium wages for a worker who worked for less than the target period
• Same Act, Article 32-5 — up to 10 hours a day for the prescribed businesses below the prescribed number of workers
• Same Act, Article 37, paragraphs 1 and 4 — at least 25 per cent and up to 50 per cent as prescribed by Cabinet Order, at least 50 per cent above 60 hours a month, and at least 25 per cent for late-night work between 10 p.m. and 5 a.m.
• Same Act, Article 66, paragraph 1 — where an expectant or nursing mother so requests, 40 hours a week and eight hours a day apply notwithstanding Article 32-2, paragraph 1, Article 32-4, paragraph 1 and Article 32-5, paragraph 1
• Same Act, Articles 89 and 90 — filing of the rules of employment by workplaces with 10 or more workers, and the hearing of opinion with the written opinion attached
• Same Act, Article 106, paragraph 1 — the duty to make the agreements known
• Ordinance for Enforcement of the Labor Standards Act (労働基準法施行規則, Ministry of Health and Welfare Ordinance No. 23 of 1947) Article 6-2, paragraphs 1, 3 and 4 — requirements for the majority representative, the prohibition of disadvantageous treatment, and the required consideration
• Same Ordinance, Article 12-2, paragraph 1; Article 12-2-2; Article 12-3; Article 12-4; Article 12-5; Article 12-6 — the first day of the period, the period of validity and Form 3-2, the items and Form 3-3 for flexitime, the ceilings and Form 4 for the one-year system, the covered businesses, the 30-person threshold, written notice and Form 5 for the one-week system, and the consideration for workers with childcare or nursing duties
• Same Ordinance, Article 25-2, paragraphs 1 to 3 — the 44-hour special measure for the businesses in items 8, 10, 13 and 14 of Appended Table 1 of the Act with fewer than 10 workers, extended to variable working hours of one month or less and to flexitime with a settlement period of one month or less. Article 32-4 of the Act is not covered
• Ministry of Health, Labour and Welfare, "A plain guide to flexitime and how to introduce it" — "as part of the work style reform, the law on flexitime was amended (in force April 2019)"; "no filing is required where the settlement period is one month or less"; overtime under flexitime is judged by reference to the settlement period
• Certified Social Insurance and Labour Consultant Act (社会保険労務士法, Act No. 89 of 1968) Article 2, paragraph 1, items 1, 1-2 and 3, and item 1 of Appended Table 1
• Statutory texts were confirmed on 22 August 2026 from the e-Gov law data API (law IDs 322AC0000000049, 322M40000100023 and 343AC1000000089). Public materials were confirmed the same day

This article does not determine whether any particular case qualifies. 四葉社会保険労務士事務所 can advise on organising the material for choosing between variable working hours and flexitime, preparing and filing labour-management agreements, amending the rules of employment and wage regulations, designing the procedure for selecting the majority representative, and reworking the premium wage calculation and the attendance cut-off after introduction. Negotiation or litigation once unpaid premium wages become contested is not handled by this office; we refer you to a lawyer (Bengoshi). Tax treatment of wages and year-end adjustment are matters we connect you with a tax accountant (Zeirishi) for, and registration with a judicial scrivener (Shiho Shoshi). Licence and permit applications are accepted by 四葉行政書士事務所, and leases of premises or company housing by 四葉不動産株式会社, each as a separate business entity. If a different professional is needed, each is contracted separately, and there is no referral fee. Frequently asked questions are collected in the FAQ.

This article is general information. Individual determinations are made by a qualified professional after a consultation, in light of individual circumstances. Written by Joji Uramatsu (Shakai Hoken Roumushi, Gyoseishoshi, Registered Real Estate Transaction Specialist).