Then the fourth angel sounded a trumpet, and the third of the sun was struck, and the third of the moon, and the third of the stars, in order that the third of them would be darkened, and the third of the day would not appear, and likewise the night.
Revelation 8:12
It is a strange vision, when read all in one breath. I imagine John watching—peering, really, into the gloom—as something inflicted the sun with a power that could diminish it by a full third of its strength. Naturally, this would dim daylight as well, perhaps in the way a room is dimmed when a light suddenly goes out. But it was not only the day that lessened. The night also got darker, as the moon and stars dimmed as well.
It had to have been chilling to see power drained from the celestial orbs.
The question remains whether day and night were lessened in power by a third, or if a third of the day and a third of the night were affected. Commentators are not agreed.

The Fourth Trumpet: the sun and moon are darkened | By Anonymous – Public Domain
Historicist
In a rather poetic way, this viewpoint interprets the sun, moon, and stars as important players in the Roman Empire’s “sky.” Invasion after invasion drained strength from Rome’s armies and wealth from Rome’s treasury. The splendor of Rome was fading.
In what would be the last of the conquests to end the dominion of the empire, Odoacer, commander of the Heruli, banished the last of the western Roman emperors in 476 CE, and abolished that role. It would be as though the sun—Sol Invictus, or Mithra of the ancient world—had been smitten, and the stars had winked out in the night sky.
Odoacer established himself as the king of Italy, and Rome’s rule continued, but in a diminished fashion.
(At least some commentators point alternatively to leaders in the church as the point of John’s vision, dulling in godly light during this time.)

Excursus: Mithra
Millennia ago, in pagan times, the last day of winter in the Northern Hemisphere was celebrated as the night the Great Mother Goddess gave birth to the baby Sun God.
Variations of this myth are found throughout the world, including Egypt, India, the Middle East, lands surrounding the Mediterranean Sea, the Celtic lands in Europe, Scandinavia, and northern Africa.
In Rome, where winters were not as harsh as those in the far north, Saturnalia—a holiday in honor of Saturn, the god of agriculture—was celebrated. Beginning in the week leading up to the winter solstice and continuing for a full month, Saturnalia was a hedonistic time, when food and drink were plentiful and the normal Roman social order was turned upside down.
For a month, slaves would become masters. Peasants were in command of the city. Businesses and schools were closed so that everyone could join in the fun.
Also around the time of the winter solstice, Romans observed Juvenalia, a feast honoring the children of Rome. In addition, members of the upper classes often celebrated the birthday of Mithra, the god of the unconquerable sun, on December 25. It was believed that Mithra, an infant god, was born of a rock. For some Romans, Mithra’s birthday was the most sacred day of the year.

Leaf disc dedicated to Sol Invictus. Silver, Roman artwork, 3rd century AD. From Pessinus (Bala-Hissar, Asia Minor). | By Unknown artist – Jastrow (2007), CC BY 2.5
Preterist
If focused on the destruction of Jerusalem, the imagery of beclouded lights becomes the deaths of both Roman and Jewish rulers who perished by ignominious means or were exiled.
Roman Emperors who were either murdered or died by suicide:
- Gaius
- Claudius
- Nero
- Galba
- Otho
- Vitellus
Jewish leaders who died in disgrace or were banished
- Herod the Great
- Herod Agrippa
- Most of the Herodian princes
- Many of the high priests
Such scholars interpret certain scriptures as assigning heavenly orbs as metaphors for leaders.
Isaiah
See, the day of the Lord is coming,
cruel, with wrath and fierce anger,
to make the earth a desolation
and to destroy its sinners from it.For the stars of the heavens and their constellations
Isaiah 13:9-11 (NRSV)—See also Isaiah 13:19, 24:19-23, 34:4-5
will not give their light;
the sun will be dark at its rising,
and the moon will not shed its light.
I will punish the world for its evil
and the wicked for their iniquity;
I will put an end to the pride of the arrogant
and lay low the insolence of tyrants.
Ezekiel
When I blot you out, I will cover the heavens
and make their stars dark;
I will cover the sun with a cloud,
and the moon shall not give its light.
All the shining lights of the heavens
I will darken above you
and put darkness on your land,
says the Lord God.… For thus says the Lord God:
Ezekiel 32:7-8, 11-12 (NRSV)
The sword of the king of Babylon shall come against you.
I will cause your hordes to fall
by the swords of mighty ones,
all of them most terrible among the nations.
They shall bring to ruin the pride of Egypt,
and all its hordes shall perish.
Joel
The earth quakes before them;
Joel 2:10 (NRSV)—See also Joel 2:28-32 and Acts 2:16-21
the heavens tremble.
The sun and the moon are darkened,
and the stars withdraw their shining.

Futurist
If John’s vision was symbolical, then these diminished lights represent fading spiritual light during the time of Tribulation. Those who remain, who have rejected the clear light of the Gospel, will now find themselves blinded by the very darkness they have chosen. The apostle Paul warned of such a deception.
For this reason God sends them a powerful delusion, leading them to believe what is false, so that all who have not believed the truth but took pleasure in unrighteousness will be condemned.
2 Thessalonians 2:11-12 (NRSV)
These allegorically lowered lights are seen in three categories:
- Sun – Highest governing authority (the Antichrist? The Beast?).
- Moon – Authority derived from the supreme ruler.
- Stars – Authority subordinated to the sun and moon.
Literal Fulfillment
However, if John’s vision was meant to be understood literally, then earth will experience physically a third less of the sun’s energy, which will directly affect the moon’s luminosity. Whatever it is that will so attack the sun will also attack the stars in our galaxy, causing a uniform dwindling of astral power across earth’s sky.
Some pose pollution as the source of this fourth disaster, so thickening the sky with impenetrable particles, the sun’s rays literally cannot pass through. Others theorize a broader cosmic event in which the sun itself, along with the rest of the galaxy’s celestial orbs, are affected.
Either way, without question, such an event would trigger the collapse of whole ecosystems, causing worldwide famine and desperate need.

Spiritual
Some interpreters who take a more metanarrative view tend to agree with historicist scholars in seeing these natural calamities in connection with the demise of the Roman Empire. And again, the eruption of Mount Vesuvius is referenced, spewing its dark ash into the sky, dimming the days, and blackening the nights.
Others believe John was speaking of the gloom of the ungodly, a motif that appears early in John’s Gospel.
And this is the judgment, that the light has come into the world, and people loved darkness rather than light because their deeds were evil.
For all who do evil hate the light and do not come to the light, so that their deeds may not be exposed.
But those who do what is true come to the light, so that it may be clearly seen that their deeds have been done in God.
John 3:19-21 (NRSV)
It is also a reminder that those who look to astrology for wisdom and direction look to lesser lights. God alone is sovereign. God is holding back judgment, darkening the sky only by a third. This is warning against choosing to enjoin godless guidance.
The four perspectives taken from Revelation: Four Views A Parallel Commentary, edited by Steve Gregg