下面句中括号部分是何成分,怎样对它提问?It's Ben' surprise birthday party (on saturday afternoon).

问题描述:

下面句中括号部分是何成分,怎样对它提问?It's Ben' surprise birthday party (on saturday afternoon).
It' Ben' surprise biernoonrthday party(on saturday afternoon)句中括号部分是party的定语还是句子的时间状语?二者的汉语译文有区别吗?

时间 What time is Ben's surprise biethday party?
=When is Ben"s surprise birthday party?