In (the) next day

[TitoBr]

Hi there!

I know that the article "the" cannot be omitted in the sentence below, but I don't know why.


I have to take a test in the next day.

Cheers,
Tito

 

[jutfrank]

Keep the but remove in.

I have to take a test the next day.

Why do you need to know why? You would use an article there in Portuguese, wouldn't you?