Revelation 9:15

So the four angels, who had been prepared for the [appointed] hour and day and month and year, were released to kill a third of mankind.

Revelation 8:7

The first [angel] sounded [his trumpet], and there was [a storm of] hail and fire, mixed with blood, and it was hurled to the earth; and a third of the earth was burned up, and a third of the trees were burned up, and all the green grass was burned up.

Revelation 9:18

A third of mankind was killed by these three plagues—by the fire and the smoke and the brimstone that came from the mouths of the horses.

Revelation 8:9

and a third of the living creatures that were in the sea died, and a third of the ships were destroyed.

Revelation 8:11-12

The name of the star is Wormwood; and a third of the waters became wormwood, and many people died from the waters, because they had become bitter (toxic).

Revelation 9:5

They were not permitted to kill anyone, but to torment and cause them extreme pain for five months; and their torment was like the torment from a scorpion when it stings a man.

Revelation 9:10

They have tails like scorpions, and stingers; and in their tails is their power to hurt people for five months.

Treasury of Scripture Knowledge

Summary

And the four angels were loosed, which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men.

An hour

Bible References

An hour

Revelation 9:5
They were not permitted to kill anyone, but to torment and cause them extreme pain for five months; and their torment was like the torment from a scorpion when it stings a man.

For to

Revelation 9:18
A third of mankind was killed by these three plagues—by the fire and the smoke and the brimstone that came from the mouths of the horses.
Revelation 8:7
The first [angel] sounded [his trumpet], and there was [a storm of] hail and fire, mixed with blood, and it was hurled to the earth; and a third of the earth was burned up, and a third of the trees were burned up, and all the green grass was burned up.