it✀s the first time that

其实真的没必要拿语法当公式学，这样很累的。很多时候通过语义分析答案就会很明晰。这句话的意思是“这是第一次什么什么”，我们可以说第一次做完了什么，也可以说第一次将要做什么，也可以说第一次正在做什么，所以后面当然可以出现不一样的时态啊。举几个例子吧。
it's the first time that he had his homework done in time.

it's the first time that he will have to face such difficulty.

it's the first time that he does housework!

回楼下的朋友：谢谢您的建议，我举的几个例子语法上都是没问题的，第一个句子在有上下文的情况下完全可以用过去完成时，第二个句子像您这么改肯定是地道一些，但这两个句子我故意这么写是为了更好的解释楼主的疑问，也即it's the first time that后面可以出现不同的时态的问题。如果都依照您的建议改过来，那三句话不都成了一般现在时了吗，呵呵。

it's the first time that he had his homework done in time.
had是否应该该has?即it's the first time that he has his homework done in time.

it's the first time that he will have to face such difficulty.
will是否应该去掉?have该has?而且该加a
it's the first time that he has to face such a difficulty.

上面两句子用it's his first time to have his homework done in time
it's his first time to face such a difficulty.
个人觉得这样较好