"the" is superfluous and awkward in this sentence. It would only be appropriate in a sentence like "you will drink until the night of your big test." The proper way to say this is "you will drink until night." To say "you will drink until the night" sounds like an incomplete thought that prompts the question, "which night?"
I find that Duolingo often falts an English translation, here for example, "until night" and seems to only accept "until the night." I read hundreds of books a year and try to follow what seems to be acceptable American English translations. I find it frustrating that Duolingo so often accepts English translations that seem unnatural and the faulty translations of non-native English speakers.