Jesus told the Church to look for the sign of the Son of Man just before the trumpet was blown for the rapture. Matthew 24:29-30.

This would occur immediately after the tribulation. The sign of the Son of Man, has been around since the opening of Genesis. Notice that Jesus only gave the unbelieving scribes of His day one sign that He was in fact the promised Messiah. He gave them the sign of Jonah. He would be in the grave three days and nights.

Jesus is the light of the world. If the light of the world was missing for three days, then the outside world went into darkness for three days. These three days of darkness, are the sign of the Son of Man.

Genesis shows three days of complete darkness before God places the sun, moon, and stars to give light upon the earth. Yes, God did say, "Let there be light," long before the fourth day. However, we are also told, that God seperated the light from the darkness. In other words, He did not permit the light to enter into the darkness.

These first three days of darkness, were to honor the time that Jesus would spend in the grave. We see these three days of darkness again and again in Scripture. When Abram makes His covenant with God, a horrible darkness descends upon him. When his descendants are delivered during the passover, we see Moses lift up his hands to bring darkness upon the land of Egypt for three days.

When Jesus hangs on the cross, we see a mini version of this sign, as three hours of darkness fall upon the land of israel. Jesus told us that the sun, moon, and stars, would cease to give their light just before He blew the trumpet for the rapture. He was quoting from Isaiah 13.