A.T. Robertson Commentary 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; that the third part of them should be darkened, and the day should not shine for the third part of it, and the night in like manner." — Revelation 8:12 (ASV)

Was smitten (επληγη). Second aorist passive indicative of πλησσω, old verb (like πληγη plague), here only in N.T.

That should be darkened (ινα σκοτισθη). Purpose clause with ινα and the first aorist passive subjunctive of σκοτιζω, from σκοτος (darkness) as in Mt 24:29, but σκοτοω in Re 9:2.

And the day should not shine (κα η ημερα μη φανη). Negative purpose clause with ινα μη and the first aorist active subjunctive of φαινω, to shed light upon, as in 18:23, not the second aorist passive subjunctive φανη with different accent. The eclipse here is only partial and is kin to the ninth Egyptian plague (Exodus 10:21).