Jesus gave the timing and described the scene of the judgment in the previous chapter:
[Mat 24:34 KJV] (34) Verily I say unto you, This generation shall not pass, till all these things be fulfilled.
He could not and did not reveal the precise hour or day or even the season of his arrival because God does not set days for judgment:
[Job 24:1 NIV] (1) "Why does the Almighty not set times for judgment? Why must those who know him look in vain for such days?
However, it did occur within 40 years of the resurrection, just as Jesus predicted.
The separation of the sheep and goats takes place in the midst of the nations but is not a judgment OF the nations; it is the judgment of the shepherds of Israel:
[Eze 34:1-31 NLT] (1) Then this message came to me from the LORD: (2) "Son of man, prophesy against the shepherds, the leaders of Israel. Give them this message from the Sovereign LORD: What sorrow awaits you shepherds who feed yourselves instead of your flocks. Shouldn't shepherds feed their sheep? (3) You drink the milk, wear the wool, and butcher the best animals, but you let your flocks starve. (4) You have not taken care of the weak. You have not tended the sick or bound up the injured. You have not gone looking for those who have wandered away and are lost. Instead, you have ruled them with harshness and cruelty. (5) So my sheep have been scattered without a shepherd, and they are easy prey for any wild animal. (6) They have wandered through all the mountains and all the hills, across the face of the earth, yet no one has gone to search for them. (7) "Therefore, you shepherds, hear the word of the LORD: (8) As surely as I live, says the Sovereign LORD, you abandoned my flock and left them to be attacked by every wild animal. And though you were my shepherds, you didn't search for my sheep when they were lost. You took care of yourselves and left the sheep to starve. (9) Therefore, you shepherds, hear the word of the LORD. (10) This is what the Sovereign LORD says: I now consider these shepherds my enemies, and I will hold them responsible for what has happened to my flock. I will take away their right to feed the flock, and I will stop them from feeding themselves. I will rescue my flock from their mouths; the sheep will no longer be their prey. (11) "For this is what the Sovereign LORD says: I myself will search and find my sheep. (12) I will be like a shepherd looking for his scattered flock. I will find my sheep and rescue them from all the places where they were scattered on that dark and cloudy day. (13) I will bring them back home to their own land of Israel from among the peoples and nations. I will feed them on the mountains of Israel and by the rivers and in all the places where people live. (14) Yes, I will give them good pastureland on the high hills of Israel. There they will lie down in pleasant places and feed in the lush pastures of the hills. (15) I myself will tend my sheep and give them a place to lie down in peace, says the Sovereign LORD. (16) I will search for my lost ones who strayed away, and I will bring them safely home again. I will bandage the injured and strengthen the weak. But I will destroy those who are fat and powerful. I will feed them, yes--feed them justice! (17) "And as for you, my flock, this is what the Sovereign LORD says to his people: I will judge between one animal of the flock and another, separating the sheep from the goats. (18) Isn't it enough for you to keep the best of the pastures for yourselves? Must you also trample down the rest? Isn't it enough for you to drink clear water for yourselves? Must you also muddy the rest with your feet? (19) Why must my flock eat what you have trampled down and drink water you have fouled? (20) "Therefore, this is what the Sovereign LORD says: I will surely judge between the fat sheep and the scrawny sheep. (21) For you fat sheep pushed and butted and crowded my sick and hungry flock until you scattered them to distant lands. (22) So I will rescue my flock, and they will no longer be abused. I will judge between one animal of the flock and another. (23) And I will set over them one shepherd, my servant David. He will feed them and be a shepherd to them. (24) And I, the LORD, will be their God, and my servant David will be a prince among my people. I, the LORD, have spoken! (25) "I will make a covenant of peace with my people and drive away the dangerous animals from the land. Then they will be able to camp safely in the wildest places and sleep in the woods without fear. (26) I will bless my people and their homes around my holy hill. And in the proper season I will send the showers they need. There will be showers of blessing. (27) The orchards and fields of my people will yield bumper crops, and everyone will live in safety. When I have broken their chains of slavery and rescued them from those who enslaved them, then they will know that I am the LORD. (28) They will no longer be prey for other nations, and wild animals will no longer devour them. They will live in safety, and no one will frighten them. (29) "And I will make their land famous for its crops, so my people will never again suffer from famines or the insults of foreign nations. (30) In this way, they will know that I, the LORD their God, am with them. And they will know that they, the people of Israel, are my people, says the Sovereign LORD. (31) You are my flock, the sheep of my pasture. You are my people, and I am your God. I, the Sovereign LORD, have spoken!"
So this judgment occurred circa 70ad when Jesus returned and judged Israel's unfaithful shepherds and set up the one true shepherd of the sheep:
[Jhn 10:10-14 KJV] (10) The thief cometh not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have it more abundantly. (11) I am the good shepherd: the good shepherd giveth his life for the sheep. (12) But he that is an hireling, and not the shepherd, whose own the sheep are not, seeth the wolf coming, and leaveth the sheep, and fleeth: and the wolf catcheth them, and scattereth the sheep. (13) The hireling fleeth, because he is an hireling, and careth not for the sheep. (14) I am the good shepherd, and know my sheep, and am known of mine.
I think we can view the 40 years from Pentecost until the Lord's return circa 70ad as the period of "proving" the people:
[Jas 1:12 KJV] (12) Blessed is the man that endureth temptation: for when he is tried, he shall receive the crown of life, which the Lord hath promised to them that love him.
IE: The judgment is a judgment by ordeal. The hopeful is tested by fire and if they endure the come forth as gold and receive the crown at the end of their race.
I like to think that Paul was not a castaway, though we do know that Moses and the whole first generation of Israel except 2 likewise were rejected. And the people celebrated idols and died in the wilderness.
Hence Paul was ever worried about his converts:
[Phl 2:16 NLT] (16) Hold firmly to the word of life; then, on the day of Christ's return, I will be proud that I did not run the race in vain and that my work was not useless.
Paul is worried that even though he was faithful, his hearers might be unfaithful and he gain a crown but lose his joy. In fact, he calls the saints his "joy and crown":
[Phl 4:1 NKJV] (1) Therefore, my beloved and longed-for brethren, my joy and crown, so stand fast in the Lord, beloved.
Jesus compared his brief trip to Heaven to a man with several slaves to whom he committed his goods, to trade with them so he could afford to pay them:
[Luk 19:11-48 NLT] (11) The crowd was listening to everything Jesus said. And because he was nearing Jerusalem, he told them a story to correct the impression that the Kingdom of God would begin right away. (12) He said, "A nobleman was called away to a distant empire to be crowned king and then return. (13) Before he left, he called together ten of his servants and divided among them ten pounds of silver, saying, 'Invest this for me while I am gone.' (14) But his people hated him and sent a delegation after him to say, 'We do not want him to be our king.' (15) "After he was crowned king, he returned and called in the servants to whom he had given the money. He wanted to find out what their profits were. (16) The first servant reported, 'Master, I invested your money and made ten times the original amount!' (17) "'Well done!' the king exclaimed. 'You are a good servant. You have been faithful with the little I entrusted to you, so you will be governor of ten cities as your reward.' (18) "The next servant reported, 'Master, I invested your money and made five times the original amount.' (19) "'Well done!' the king said. 'You will be governor over five cities.' (20) "But the third servant brought back only the original amount of money and said, 'Master, I hid your money and kept it safe. (21) I was afraid because you are a hard man to deal with, taking what isn't yours and harvesting crops you didn't plant.' (22) "'You wicked servant!' the king roared. 'Your own words condemn you. If you knew that I'm a hard man who takes what isn't mine and harvests crops I didn't plant, (23) why didn't you deposit my money in the bank? At least I could have gotten some interest on it.' (24) "Then, turning to the others standing nearby, the king ordered, 'Take the money from this servant, and give it to the one who has ten pounds.' (25) "'But, master,' they said, 'he already has ten pounds!' (26) "'Yes,' the king replied, 'and to those who use well what they are given, even more will be given. But from those who do nothing, even what little they have will be taken away. (27) And as for these enemies of mine who didn't want me to be their king--bring them in and execute them right here in front of me.'" (28) After telling this story, Jesus went on toward Jerusalem, walking ahead of his disciples. (29) As he came to the towns of Bethphage and Bethany on the Mount of Olives, he sent two disciples ahead. (30) "Go into that village over there," he told them. "As you enter it, you will see a young donkey tied there that no one has ever ridden. Untie it and bring it here. (31) If anyone asks, 'Why are you untying that colt?' just say, 'The Lord needs it.'" (32) So they went and found the colt, just as Jesus had said. (33) And sure enough, as they were untying it, the owners asked them, "Why are you untying that colt?" (34) And the disciples simply replied, "The Lord needs it." (35) So they brought the colt to Jesus and threw their garments over it for him to ride on. (36) As he rode along, the crowds spread out their garments on the road ahead of him. (37) When he reached the place where the road started down the Mount of Olives, all of his followers began to shout and sing as they walked along, praising God for all the wonderful miracles they had seen. (38) "Blessings on the King who comes in the name of the LORD! Peace in heaven, and glory in highest heaven!" (39) But some of the Pharisees among the crowd said, "Teacher, rebuke your followers for saying things like that!" (40) He replied, "If they kept quiet, the stones along the road would burst into cheers!" (41) But as he came closer to Jerusalem and saw the city ahead, he began to weep. (42) "How I wish today that you of all people would understand the way to peace. But now it is too late, and peace is hidden from your eyes. (43) Before long your enemies will build ramparts against your walls and encircle you and close in on you from every side. (44) They will crush you into the ground, and your children with you. Your enemies will not leave a single stone in place, because you did not accept your opportunity for salvation." (45) Then Jesus entered the Temple and began to drive out the people selling animals for sacrifices. (46) He said to them, "The Scriptures declare, 'My Temple will be a house of prayer,' but you have turned it into a den of thieves." (47) After that, he taught daily in the Temple, but the leading priests, the teachers of religious law, and the other leaders of the people began planning how to kill him. (48) But they could think of nothing, because all the people hung on every word he said.
Again, he is describing his brief going away and his soon return:
[Jhn 14:1-4 KJV] (1) Let not your heart be troubled: ye believe in God, believe also in me. (2) In my Father's house are many mansions: if it were not so, I would have told you. I go to prepare a place for you. (3) And if I go and prepare a place for you, I will come again, and receive you unto myself; that where I am, there ye may be also. (4) And whither I go ye know, and the way ye know.
It all went down circa 70ad.