Employees usually need to ask for permission from their boss for leave, which is called qingjia in Chinese. But on certain occasions like the first day of work after the Spring Festival, many employees fail to show up to work without asking for permission. Most cook up excuses like flight delays, leaving the boss no choice but to grant them the leave. Thus, a fait accompli leave: the leave is already taken, and there is no point denying it. If something is a fait accompli, it has already been decided or done and cannot be changed.

员工通常需要经过老板允许才能休假，这在中文里叫“请假”。但是，在一些特殊时期，比如春节过后的首个工作日，很多员工都没有回来上班，但也没有请假，大部分都以航班延误等作为晚归理由。老板无奈，也只能准假。这种情况就叫“霸王假”，人家既然都没来上班，你否决也没有意义了。fait accompli表示既成事实，也就是无法更改或撤销的事实。

For example:

Nearly half of the staff didn't show up for work after the New Year holiday, it seems they all took fait accompli leave.

新年假期结束后有近一半的员工没有来上班，貌似都请了“霸王假”啊。