Feifei Wang
It means working from 9 am to 9 pm, 6 days a week.
It started to gain popularity when some Chinese company, predominately tech companies (and game companies) would openly require their workers to work for 12 hours a day, 6 days a week, without overtime pay.
It is listed on their hiring ads.
It is, of course, against Chinese labor law. But speaking from the gaming industry (since I’m more familiar with it), nobody enforces the law. And the companies would say the workers volunteered to stay late to finish the work.
What came after 996? ICU.
you work that much with that kind of intensity, you end up in ICU sooner or later.

"996"(九九六)意味着每周工作6天,每天工作时间从早上9点持续到晚上9点。它开始在中国流行起来时,一些公司,尤其是科技公司(以及游戏公司),公开要求员工每天工作12小时,每周工作6天,而且没有加班费。这种工作制度在他们的招聘广告中会明确列出。
当然,这违反了中国的劳动法。但就我对游戏行业的了解,没有人执行这项法律。公司会说员工自愿加班以完成工作。
在“996”之后出现的是“ICU”。如果你长时间以如此高强度地工作,迟早会进入重症监护室(ICU)。