Revelation 8:12: And the fourth angel sounded, and the third part of the sun was smitten, and the third part of the moon, and the third part of the stars; so as the third part of them was darkened, and the day shone not for a third part of it, and the night likewise.

The fourth trumpet angel of the seventh seal is the antitype for the ninth Egyptian plague in the days of Moses when there were three days of thick (total) darkness.¹ Some scholars incorrectly speculate that the sun, moon, and stars in this fourth trumpet plague represent people and events in history.² Others believe the smoke and pollution from first three plagues cause the darkness of the fourth plague.³ If that was true, however, the darkness would be a continuation of the first three plagues rather than the start of a fourth and separate trumpet plague.⁴

The sun, moon, and stars will be darkened through God's power during the fourth trumpet plague, and then the light will be miraculously restored.⁵ Since the light of Christ is the source of power that illuminates the sun, moon, and stars,⁶ the darkness may occur simply because the light of Christ is withdrawn.⁷ In the beginning of the physical creation Christ caused darkness to come up upon the face of the deep and then he caused light to appear⁸ with the words, let there be light.⁹ He therefore has the power to cause total darkness to appear by the power of his word.¹⁰

The sun, moon, and stars will be smitten during the fourth trumpet plague.¹¹ This means the earth will be subject to total physical darkness¹² rather than spiritual darkness such as the fifth trumpet angel (First Woe) in Revelation chapter 9.¹³ There is ample scriptural precedent for total darkness in history. There was total darkness at the time of the Egyptian plagues,¹⁴ and also in Judea¹⁵ and America when Christ was crucified.¹⁶ The three hours of destruction and complete darkness for three days in America is the pattern and model for the Second Coming.¹⁷ John's vision repeats this pattern with the three trumpet plagues of destruction followed by complete darkness.¹⁸ After the darkness in America, Christ appeared among the more righteous Nephite survivors,¹⁹ just as he will appear at his Second Coming among the more righteous people that survive the plagues and darkness of the sixth²⁰ and seventh seals.²¹

Many scriptures predict that the sun, moon, and stars will literally become dark,²² starting with the darkness predicted by John at the end of the sixth seal in Revelation 6:12-13.²³ Prophecies of darkness can be found in the Old Testament,²⁴ the New Testament,²⁵ the Book of Mormon,²⁶ the Doctrine and Covenants²⁷ and the Pearl of Great Price.²⁸ The sun, moon, and stars will be dark on at least three future occasions. These include the end of the sixth seal,²⁹ at the time of Christ's Second Coming³⁰ and at the end of the earth after the millennium.³¹

When the third part of the sun, moon, and stars are smitten during the fourth trumpet plague, there will be total darkness for one third part of a day and night (i.e., 8 hours).³² John describes this by saying, the day shone not for a third part of it, and the night likewise. This brief period of darkness will be a discernable sign of the times.³³ By this sign the wicked shall surely know that God's judgments are ready to fall upon them³⁴ and fear shall come upon the unrepentant.³⁵ They that already walk in spiritual darkness³⁶ shall see and feel the physical darkness of that day.³⁷

Darkness will also come upon the earth before the Second Coming during the fifth Vial Plague in Revelation 16:10, but it will be a spiritual darkness rather than the physical darkness present during the fourth trumpet plague.³⁸ The total and enduring spiritual darkness of the Fifth Vial Plague will smite Satan's kingdom, setting the stage for Spiritual Armageddon.³⁹