把这句话补形：
(When you )thought (it) is already (it) is late,exactly (it ) is the earliest time.
When you 可以省略
主要是it 首先,两个分句的后一个it相同,也就是主语相同,那么它们就能省略,甚至连is都可以.而第一个it是形势主语,意思是这已经是...
举个例子,比如it is already for him to go
如有错,请多包涵