Both prophecies in Revelation and Joel
speak of a day of darkness. . .

The Day of the Lord is introduced with
the darkening of the sun and moon. The
Fourth Trumpet, before the Fifth Trumpet
was the same. "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."
Revelation 8:12

The Fifth Trumpet has a darkening of
the sun by the smoke from the Bottom-
less Pit. Revelation 9:2 And the prophecy
of Joel 2:2 also speaks of this day of
darkness.