労働基準法の基本 — 労働時間・休憩・残業規制

The Labor Standards Act (LSA, "Roukihou"), enacted in 1947, is the law that establishes minimum standards for protecting workers. It defines the minimum working conditions employers must comply with, and violations carry criminal penalties. This article organizes the basic rules concerning working hours, breaks, holidays, and overtime.

LSA Article 32 sets the maximum hours an employer may have a worker work as "8 hours per day and 40 hours per week." Exceeding these limits requires conclusion and filing of a 36-Agreement (described below). As a special exception, workplaces in commerce, film, health, or hospitality industries that routinely employ fewer than 10 people may go up to 44 hours per week.

LSA Article 34 stipulates that for working hours exceeding 6 hours, employers must grant at least 45 minutes of break, and for hours exceeding 8 hours, at least 60 minutes (1 hour), given during the workday. Three principles apply to breaks: (1) granted mid-shift, (2) granted simultaneously to all workers, and (3) free to use as the worker chooses. On-call time such as phone duty does not count as a break.

LSA Article 35 stipulates that employers must grant at least one day of holiday per week — the "weekly holiday system." Alternatively, the law permits a "variable weekly holiday system" granting 4 or more holidays over a 4-week period (Art. 35 para. 2). National public holidays and the New Year period are not statutory holidays but "designated holidays" set by company work rules.

To order work exceeding the statutory working hours or on a statutory holiday, the employer must conclude a written agreement with a representative of the majority of workers (the labor union, or an elected employee representative) and file it with the competent Labor Standards Inspection Office. Because this is based on LSA Article 36, it is called a "36-Agreement (Sabu-roku Kyoutei)." Overtime without this filing is immediately illegal.

Under the Work-Style Reform Related Laws, from April 2019 (April 2020 for SMEs), penalty-backed upper limits on overtime were written into law for the first time. The principle: 45 hours per month and 360 hours per year. These figures match the previous administrative guideline, but with statutory force, violations now carry up to 6 months' imprisonment or a fine of up to 300,000 yen.

With a special clause for temporary or special circumstances, employers may order overtime exceeding the principle, but cannot exceed these four absolute limits: (1) within 720 hours per year, (2) less than 100 hours per month including holiday work, (3) average within 80 hours per month over 2-6 months including holiday work, and (4) the principle of 45 hours per month may be exceeded only 6 times per year. These standards are designed around the "karoshi line" (80-100 monthly overtime hours associated with death from overwork).

LSA Article 37 obligates employers to pay a premium on top of normal wages for overtime, holiday, and late-night work. The rates are: overtime (portion exceeding statutory hours) 25% or more, late-night (10 PM-5 AM) 25% or more, and statutory holiday work 35% or more. When overtime overlaps with late-night, the premium becomes 50%; holiday plus late-night becomes 60%.

For overtime exceeding 60 hours per month, the 2010 amendment applied a 50%-or-more premium to large corporations. From April 2023, the same 50% rate was extended to SMEs as well. As a result, overtime exceeding 60 hours per month at any company carries a mandatory minimum 50% premium.

LSA Article 41 stipulates that for persons in supervisory or management positions (so-called "managerial supervisors"), the provisions on working hours, breaks, and holidays do not apply. Note, however, that the late-night premium does still apply. Regarding the "manager in name only" problem, case law shows that a title alone does not qualify someone as a managerial supervisor — three substantive elements are required: (1) integration with management, (2) freedom over attendance, and (3) appropriate compensation.

LSA violations carry penalties, with both the legal entity and the individual actor subject to punishment (dual-penalty provision, Art. 121). Main penalties: violations of working hours (Art. 32), breaks (Art. 34), holidays (Art. 35), and premium wages (Art. 37) carry up to 6 months' imprisonment or a fine of up to 300,000 yen (Art. 119). Forced labor (Art. 5) violations carry the most severe penalty: 1-10 years' imprisonment or a fine of 200,000 to 3,000,000 yen (Art. 117).

Enforcement of the LSA is handled by the Labor Standards Inspection Office ("Roukisho"), a branch agency of the Ministry of Health, Labour and Welfare. Labor Standards Inspectors are special judicial police officers with authority to conduct on-site workplace inspections, request submission of records and documents, interrogate employers and workers, and even arrest and refer cases to prosecution (Articles 101-102).

Companies should pay particular attention to: (1) The 2017 guideline mandates objective attendance management (time cards, IC cards, PC logs, etc.). (2) Working hours include all time under the employer's command — changing clothes, morning meetings, training, travel time, etc. (Supreme Court ruling, Mitsubishi Heavy Industries Nagasaki Shipyard, March 9, 2000). (3) The statute of limitations for unpaid overtime was extended from 2 to 3 years in the 2020 amendment (currently 3 years, scheduled to align to 5 years in the future).