"If people sat outside and looked at the stars each night I bet they'd live a lot differently. When you look into infinity, you realize there are more important things than what people do all day." - Calvin & Hobbs
Night time usually symbolizes calm and peace. In The Night Circus, I think thats what it symbolized at night everything was serenity. It also was used to depict some character's personalities. Like the circus performers, able to do all that magic and illusions.
The fiery depths of space: Astronomers capture dazzling rainbow nebula swirling round supergiant star