The 996 working hour system (Chinese: 996工作制) is a work schedule practiced by some companies in the People's Republic of China. It derives its name from its requirement that employees work from 9:00 am to 9:00 pm, 6 days per week; i.e. 72 hours per week. A number of Mainland Chinese internet companies have adopted this system as their official work schedule. Critics argue that the 996 working hour system is a violation of Chinese Labour Law and have called it "modern slavery".