Originally, presence, from παρεῖναι, to be present. In this sense in Phi 2:12; 2Co 10:10. Also arrival, as in 1Co 16:17; 2Co 7:6, 2Co 7:7; 2Th 2:9; 2Pe 3:12. Of the second coming of Christ: Jam 5:8; 1Jo 2:28; 2Pe 3:4; 1Th 4:15.
Of the world (αἰῶνος)
Rather the existing, current age. They do not ask the signs of the Messiah's coming at the end of all time, to judge the world.