The conjunction ora che has no correspondent conjunction in English, normally it is to be translated with Time has come. Beside that, even if ora che is normally considered as a conjunction in grammar books, actually it is not a conjunction at all, because it introduces a relative clause and not a subordinate clause. The litteral translation would be it is the hour that and the following relative clause would specify the hour.
~It is the hour that I tell you the truth.~
Time has come that I tell you the truth.
We follow the example of the Italian grammar books. One argument to consider ora che as a conjunction is the fact that it establishes a temporal relationship between the main clause and the relative clause.
È ora che lo dica: ti amo!
Time has come to say it: I love you!
If the action / event is not real the congiuntivo is used.
"Ora che" together with the congiuntivo points to a possibility, a hypothetical relationship
È ora che lo faccia anche io!
It' s time that I do it as well.
Ora che lo dici lo noto anche io.
Now that you say it, I notice it as well.
Ora che lo fa lui sembra la fine del mondo!
Now that he does it, it seems to be the end of the world.
Non voleva lasciare il Messico, ma ora che ha fatto il grande passo non vuole più ritornarci a vivere.
He didn' t want to leave Mexico but now, after having done the big step, he doesn' t want to return.
Ora che aveva fatto il suo dovere, poteva guardare i suoi nipoti.
Now that he has finished his duties, he was able to regard his grandsons.