fifteen days
关他十五天!
Lock him up for fifteen days!
— 放牛班的春天 (2004)
曹斌十五天十五天内我必须要见到这个人
Cao Bin, fifteen days—I've got to see this person within fifteen days.
— Dying to Survive (2018)
十五天快到了人必须抓到局长
There are only fifteen days left. We have to catch the director.