Quote:
Originally Posted by matilda  at night:(11-6 am).
by night:until night. until 11 may be.
no idea about the third sentence |
At night and
in the night are both good. By night is a little more complicated as there I have heard some variations between AE and BE and also regionally in the UK.
I have not heard it used in the sense of until a certain time, but I wouldn't be surprised if this is common to other native speakers. Phrases like "travelling by night" and "working day by day" are very common. In your example I think 1 and 3 are the best.