4.5-Day Work Week · Reduced Working Hours
4.5-Day Workweek and Working Time Reduction
What is a 4.5-day work week?
- A work arrangement based on labor-management agreement, not a statutory system
- First, decide whether you are cutting hours or rearranging them
- Hurdles: hourly ordinary wage, leave units, and rules of employment
If you treat the 4.5-day week as just 'a perk of leaving early on Friday afternoon,' the design will go off track. The first thing to settle is whether you are actually reducing contractual working hours, or keeping total hours the same and only rearranging them. The first cuts a 40-hour week to around 36 hours; the second adds an hour a day Monday through Thursday and makes Friday a half day. They look the same, but pay, allowances, and leave calculations work out very differently. Statutory working hours are still 40 per week, and no law makes the 4.5-day week mandatory.
There are four types. The reduction type cuts scheduled working hours without cutting pay. The compressed type uses selective or flexible working hours to fit 40 hours into 4.5 days. The biweekly 4-day type gives employees every other Friday off. The annual-leave type encourages taking a half day of leave on Friday afternoons. That last type doesn’t reduce working hours; it only uses up personal leave, so it is hard to call it a true reduction. For the compressed type, you need rules of employment that allow the system and a written agreement with the worker representative. Without both, hours beyond 8 a day count as overtime.
The reduction type has three pressure points. If you cut contractual hours while keeping monthly pay, the hourly ordinary wage rises, and so do the rates for overtime, night, and holiday pay. You also need to decide in advance how to pay for hours worked beyond the reduced schedule but still within 40 a week. Because daily hours now differ by weekday, manage annual leave in hours rather than days so that deductions on a half day are fair. Amending the rules of employment is mandatory, and if anyone ends up with lower pay or allowances, it counts as an unfavorable change and requires majority consent.
The point where things most often go wrong in practice is fairness. If only office staff leave early on Friday while shift-based production and customer-facing teams stay the same, the policy becomes a source of conflict. It is also common to cut hours without cutting workload, so that Friday afternoon turns into overtime done from home, and unrecorded work can then become a wage arrears issue. On the policy side, the government and some local governments run programs that support companies adopting the model, and related legislation is under discussion. Eligibility, requirements, and amounts may change, so check the latest announcements from the Ministry of Employment and Labor and the program operators.
Jongmu KimSpecialist in corporate talent development and job competency building
Hwi KimCEO of HRDIST & talent development system consultant| Type | Weekly working hours | Impact on pay and allowances | Required steps |
|---|---|---|---|
| Reduction type | Fewer than 40 hours | Hourly ordinary wage rises if monthly pay is kept | Amend the rules of employment and design pay |
| Compressed | Stays at 40 hours | Little change | Requirements for adopting selective or flexible working hours |
| Biweekly 4-day type | Reduced or unchanged on a two-week average | Depends on design | Amend the rules of employment and define the day off |
| Leave-based | No change | None (uses personal leave) | Only encourages taking leave |
The 4.5-day week is not defined in law. It is a practical work arrangement that grew out of the 4-day week debate. The Labor Standards Act only sets a cap of 40 working hours per week; shorter schedules are set by employer and employees through work rules and mutual agreement. Government support and legislation are still at the discussion or pilot stage, so details may change.
Let’s look at a hypothetical case. Company A, which makes industrial sensors, has 210 employees: 130 office and R&D staff and 80 production workers on two shifts. When applications for developer openings fell 40% in a year, the CEO told the team to look into adopting a 4.5-day week.
- After the HR director compared the four types and submitted the report, the CEO chose the reduction type with no pay cut. The finance director said, "First, let’s see how much production overtime pay goes up if the hourly ordinary wage rises."
- The calculation showed that cutting contractual hours to 36 per week would raise the hourly ordinary wage by about 11% and add KRW 240 million (≈ US$179,600) a year in overtime pay alone. The company accepted this on the condition that it would reduce overtime.
- Production staff could not take Friday half-days, so the company drew up a new shift schedule that gives them one day off every other week. The head of production said, "If only office staff get time off, the line will complain," and asked that both groups start in the same month.
- Annual leave was switched to an hourly basis, so a Friday off deducts only 4 hours. The proposed change to the work rules went through a consultation with a majority of employees and passed with 87% in favor.
- During a three-month pilot, system access logs showed 38 employees logging in on Friday afternoons. HR cut meetings from 14 to 9 a week and blocked messenger notifications on Friday afternoons.
- One year after rollout, applications per developer opening rose from an average of 23 to 41, and turnover fell from 14% to 9%. Monthly overtime per person dropped from 16 hours to 9 hours.