It is (high) time that 后面的从句谓语动词要用过去式或用should加动词原形，但should不可省略。如：
　 It is time that the children went to bed.
　 It is high time that the children should go to bed.

It is high time that 这是一个虚拟语气的句型，后面的谓语动词有两种：1.动词的过去式2.should+动词原形，但是should不能省略；