The expression by night is usually accustomed to contrast an individual's nighttime pursuits for their daytime pursuits, particularly when the nighttime pursuits are abnormal or unforeseen. You will notice it quite usually in the construction X by day, Y by night. Some examples: playful environment that appeals to younger crowds https://andren4x74.blogdigy.com/helping-the-others-realize-the-advantages-of-night-gangnam-퍼펙트가라오케-karaoke-guide-58499735