Poisonings are legal in any of those places, though. Attacks of any kind can be made outside those places, for example, in the Siegel courtyard. Everyone has a different sleep schedule. Attacks with weapons during these hours can only be made outdoors. Same with bombs that make noise.
Poisons are legal at any time.
Note that you can attack through an open window. Attacking anyone else by any means is considered attacking an innocent bystander, which is bad. Very, very bad. Accidental death is different. But if player A intentionally kills player C, player A is penalized and player C remains in the game.