"You read at night."
Translation:Vous lisez la nuit.
Well the sentence is not well translated in my opinion.
"Vous lisez dans la nuit" = "You read in the night"
"Vous lisez la nuit" = "You read at night"
As for your questions @danapplegate, I suppose you're asking if there is a possibility to translate "at night" with "à la nuit" to which the answer is no.
Maybe there are sentences using "à la nuit" but I can't think about any right now, and they would likely have no link with this exercise.
They're both translated with "la nuit", they don't mean the same thing. In French, context is needed to tell them apart.
I still don't understand WHY we're to use la instead of à la. Seems to go against the logic of this exercise.
Searching for logical explanations is not always a good way to learn a new language, because all languages have different logic patterns, and most of them have exceptions. As a matter of fact, French has a tremendous amount of exceptions (which is part of the reason many people find it difficult to learn).
We usually don't use "à" when we talk about a whole portion of time (unless we use an expression that requires to use "à", for example "par rapport à").
"Le hibou dort le jour et chasse la nuit." = "The owl sleeps during the day and hunts at night."
However we use it for exact moments in time, for example:
"Il est arrivé à 15:00." = "He arrived at 3 o'clock."
You can learn more about "à" here: