In recent months, we’ve had a wave of consultations about working hours. Members are being told they must work Saturdays, or that even if their week tops 40 hours, there’s “no overtime” because of something called the variable working hours system (変形労働時間制). Let’s clear up what this actually means—and what you should be checking in your own workplace.

Some employers say “no overtime pay” because of variable hours systems. Don’t take their word for it.
✔️ Daily cap: 10 hours max
✔️ Weekly average: 40 hours
✔️ Agreement required: Must be signed by a properly elected workers’ rep or majority union
✔️ Transparency: You have the right to see the agreement or work rules

🚩 Red flags: No election for the rep., sudden schedule changes, “no overtime pay ever”

If you’re unsure whether your company’s system is legitimate, contact the General Union. We’ll check the documents and stand with you.

The Basics

Japan’s labour law normally sets a hard ceiling: 8 hours a day, 40 hours a week. Under variable systems, employers can move hours around: longer on busy days, shorter on quiet ones, so long as the average stays within the legal weekly limit over a set period.

There are four types:

• Weekly system: For small shops, restaurants, or hotels. Rarely seen elsewhere.
• Monthly system: Hours can be concentrated within a one-month period. Still capped at 10 per day, with a clear written schedule required.
• Annual system: Spreads hours over up to a year, but with strict safeguards: daily max 10, weekly max 52, and limits on consecutive working days.
• Flextime system: Workers set their own start/finish within “core hours,” balancing to 40 hours a week on average over a period of up to 3 months.

Why Employers Like It

Employers often push variable systems because it cuts overtime bills and lets them pack hours into crunch periods. That’s legal—but only if the paperwork is airtight.

Agreements and Worker Representatives

This is where many workplaces fail. To be valid, a variable hours system needs either:

• A union representing a majority of workers at the workplace, or
• A properly elected workers’ representative to sign the agreement.

“Appointed” reps chosen by management don’t count. If the representative wasn’t really elected, the whole agreement may be invalid.

That means you should be asking:

• Can I see the labour–management agreement or the work rules?
• Who signed on behalf of workers?
• When was the election held?

In reality, we often find: there’s no agreement, no filed work rules, no rep, or a “rep” hand-picked by the company. None of these hold legal water.

Questions We Hear From Members

“Can they make me work Saturdays?”
Only if the schedule complies with the law. Saturdays aren’t special in the law; what matters is that you still get your statutory days off and the average stays legal.

“I worked 42 hours this week—do I get overtime?”
Not automatically. Under variable systems, the test is the average across the set period. But any breach of daily caps or total limits still counts as overtime.

“They won’t show me the agreement.”
Treat that as if no agreement exists. Transparency is required.

Red Flags

• “No overtime ever” under variable hours
• Schedule changes with no notice
• Contracts with no clear working hours
• Employers refusing to disclose agreements
• Worker reps who were never elected

Bottom Line

Variable systems are complicated, and employers often use them as cover for overwork. The safest step is simple: ask to see the documents, check who signed them, and don’t take the company’s word for it.

If you’re not sure your workplace system is legitimate—or if you’re being told you must work extra without overtime—contact the General Union. We’ll review your schedule, the agreements, and your rights, and stand with you to make sure the rules are enforced.

Read the General Union Guide to Variable Workers Hours Systems at gu.genu.cc/vwh