All this must be done before the second coming of Christ

Joseph Smith The coming of the Son of Man never will be—never can be, till the judgments spoken of for this hour are poured out: which judgments are commenced. Paul says, “Ye are the children of the light, and not of the darkness, that that day should overtake you as a thief in the night.” It is not the design of the Almighty to come upon the earth and crush it and grind it to powder, but he will reveal it to His servants the prophets. Judah must return, Jerusalem must be rebuilt, and the temple, and water come out from under the temple, and the waters of the Dead Sea be healed. It will take some time to rebuild the walls of the city and the temple, and etc; and all this must be done before the Son of Man will make His appearance. There will be wars and rumors of wars, signs in the heavens above and on the earth beneath, the sun turned into darkness and the moon to blood, earthquakes in divers places, the seas heaving beyond their bounds; then will appear one grand sign of the Son of Man in heaven. But what will the world do? They will say it is a planet, a comet, etc. But the Son of Man will come as the sign of the coming of the Son of Man, which will be as the light of the morning cometh out of the east. (General conference, speaking on the judgments to come before the Second Coming of Christ, April 1843) HC5:336-37