In Portuguese, “yesterday” is ontem. You may hear the phrase à noite, which may sound like Spanish anoche–but it is not. À noite simply means “at night.” To say “last night” (Span anoche), use ontem à noite. Depending on context, “tonight” can be either hoje à noite or, simply, à noite (in contexts where it is clear that one is talking about today/tonight).
English: Did you go out last night?
Spanish: ¿Saliste anoche?
Portuguese: Você saiu ontem à noite?