¡°Back in the day,¡± said Lim Hyung-kyu, a retired Samsung Electronics executive now in his 70s, ¡°my weeks were Monday, Tuesday, Wednesday, Thursday, Friday, Friday, Friday.¡±

Lim joined Samsung, South Korea¡¯s largest company, in 1976 and rose through the ranks to chief technology officer.

For much of his 30-plus years at Samsung, working on the weekends was normal ¡ª and legal under the nation¡¯s labor laws.