Night is often symbolic of evil and death. It comes to represent those ideas in the concentration camps where Elie Wiesel focuses most of his narrative, and it also comes to represent a world where he feels that God has abandoned him, leaving him in a spiritual darkness, or night. Often, the worst of his suffering, both physically and mentally, occurs at night.

Much of this symbolism is captured in the following quote found in Chapter 3:

Never shall I forget that night, the first night in camp, that turned my life into one long night seven times sealed.

Never shall I forget that smoke.

Never shall I forget the small faces of the children whose bodies I saw transformed into smoke under a silent sky.

Never shall I forget those flames that consumed my faith forever.

Never shall I forget the nocturnal silence that deprived me for all eternity of the desire to live.

Never shall I forget those moments that murdered my God and my soul and turned my dreams to ashes.

In this quote, Elie equates night with loss and death. He faces the horrendous murder of innocent children. He feels that his faith is consumed by the fires of the incinerators. And he feels that God has forsaken all of them. In all of this, Elie recalls a "nocturnal silence" that offers no path of redemption. All around him, the darkness of night presses in and swallows parts of his soul.

Later after many days in the concentration camp, Elie's friend Akiba Drumer loses all hope, telling everyone that he can't go on. He goes even further to say that God is not with them, and Elie knows that his death is imminent because he has lost the will to live. Elie feels that this complete loss of faith is the reason Akiba "offer[ed] his own neck to the executioner" at the next selection.

Elie follows this narration with further symbolism of night:

Winter had come. The days were short, and the nights had become almost unbearable. In the first hours of dawn, the icy wind cut us like a whip. We were given winter clothes-slightly thicker striped shirts. The veterans found in this a new source of derision.

“Now you’ll really be getting a taste of the camp!”

We left for work as usual, our bodies frozen. The stones were so cold that it seemed as though our hands would be glued to them if we touched them. But you get used to anything.

The suffering Elie endures is captured in the symbolism of night, but unlike Akiba, he is able to endure it and maintain a sense of hope. Because he can "get used to anything," he shows his ability to adapt even under evil circumstances. Unlike Akiba who could not make it through another night, Elie survives because of his determination to endure and survive.

This shows that Elie understands another truth about night: it always gives way to day. Elie knows that if he can survive each night—each attempt to destroy his life—the sun will rise again, and he clings to the hope of living in light and away from evil through his spirit of determination.

What is the significance of "night" in the novel Night?

Night is "cover of darkness" also.  We must not forget to consider color symbols...black is almost never used in a story to indicate positive outcomes or personality traits.  It is in the dark that people who intend to do evil deeds play them out...so they will not be seen or caught.  In this book, the night symbolizes cold, lonely, and unfriendly times.  People freeze and starve and die in the night. 

It is very significant.  The title of the book refers to the fear and safety that the cover of night brings. Night is the time when the SS came for the prominent Jews in the communities both before the Jews were evacuated to the concentration camps and also in the camps themselves.  In this regard, night was a time to be feared since you couldn't see what was coming.  In the book, the victims of the concentration camps could let down their guard a little at night where no one could see them, and they could cry or not be so careful with facial expressions.  In this regard, night was a time of comfort and relaxation.  It was a cruel, double-edged sword.

One important quote in the book which really points to the purpose of the title is:

Never shall I forget that night, that first night in camp, which has turned my life into one long night, seven times cursed and seven times sealed...Never shall I forget those moments which murdered my God and my soul and turned my dreams to dust.  Never shall I forget these things, even if I am condemned to live as long as God Himself. Never.     Chapter 3, page 32.