Filmtips:
Day for night, also known as nuit américaine ("American night"), is the name for cinematographic techniques used to simulate a night scene; such as using tungsten-balanced rather than daylight-balanced film stock or with special blue filters and also under-exposing the shot (usually in post-production) to create the illusion of darkness or moonlight.
Historically, infrared movie film was used to achieve an equivalent look with black-and-white film.