Question

It's high time that是定语从句当先行词不作宾语时为什么that可以省略呀 求解TAT

Answer 1

It's high time that这是个虚拟语气的主要结构，意思是是时候做某事了。

完整成分是It is (high) time (that) sb. did/should do

按语法规定可以省略的。