{The sun shall be darkened} (ho helios skotisth(8873)etai).
Future passive indicative. These figures come from the prophets
( Isa 13:9f.  Eze 32:7f.  Joe 2:1f.,10f.  Am 8:9  Zep 1:14-16  Zec 12:12 ). One should not forget that prophetic imagery was not
always meant to be taken literally, especially apocalyptic
symbols. Peter in  Ac 2:15-21  applies the prophecy of Joel about
the sun and moon to the events on the day of Pentecost. See on
烘t 24:29-31| for details of verses  24-27 .