From Sunday, South Korean employees' work week has been limited to a maximum of 52 hours.
The government's initiative to strike a better work-life balance bans businesses with more than 300 employees from running a system of more than 40 hours of regular work and 12 hours of extra work time.
After a six-month grace period, business owners caught not following the new rules can face up to two years of prison time or a fine of up to 20 million won or nearly 18-thousand dollars.
According to a recent survey by the Labor Ministry, some 60 percent of the country's big businesses have already implemented the system.
Korea's leading retailers have adjusted their opening time for employees of their subcontractors, which the employees say has already been making a difference.
"Since I go to work a bit later, I can afford some time to spare in the crowded subway and after arriving at work, I have enough time to prepare before opening time."
Retailers' earlier closing times are expected to reflect changes in consumers' shopping patterns from the reduced workweek, and are also benefitting employees.
"We the employees are the most satisfied with not having to deal with the inconvenience from being unable to use public transportation after closing."
However, a problem lies with small and medium-sized companies which have been faced with difficulties such as maintaining their production volume and dealing with the rising labor costs.
While some companies want a more flexible system of increasing hours during more demanding weeks, and reducing hours for other weeks, the labor sector argues that would ultimately lead to extended hours.
Choi You Sun, KBS World Radio News.
In the public sector the move to improve work-life balance began earlier. Nearly nine out of ten public organizations in South Korea had already introduced flexible working hours well before the country's recent introduction of the 52-hour workweek system.
According to state portal All Public Information in One on Wednesday, 321 of 361 state-run institutions, or 88-point-nine percent, adopted a flexible work system last year.