Dan 7:9 I beheld till the thrones were cast down, and the Ancient of days did sit, whose garment was white as snow, and the hair of his head like the pure wool: his throne was like the fiery flame, and his wheels as burning fire.
Dan 7:10 A fiery stream issued and came forth from before him: thousand thousands ministered unto him, and ten thousand times ten thousand stood before him: the judgment was set, and the books were opened.
So the judgment happens after the reign of 4th beast power. that is after 1798. This judgment is investigative in nature. There terms like the judgment was set and books were opened shows us that the judgment was investigative in nature.
Act 3:19 Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord;
So the blotting out of sins from the records we saw in Dan 7:10 happens in future.
This judgement should be only for saints, why?
1Pe 4:17 For the time is come that judgment must begin at the house of God: and if it first begin at us, what shall the end be of them that obey not the gospel of God?
Bible says Judgment begins in the house of God i.e., righteous will be judged first.
The judgment of the wicked happens in the millennium.
1Co 6:2 Do ye not know that the saints shall judge the world? and if the world shall be judged by you, are ye unworthy to judge the smallest matters?
1Co 6:3 Know ye not that we shall judge angels? how much more things that pertain to this life?
So the saints judge both the wicked men and fallen angels
Rev 20:4 And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years.
Rev 20:5 But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection.
The saints judge the wicked in the millennium.
The wicked who will be part of second resurrection will be receiving their punishment after the third coming of Lord.
Rev 20:9 And they went up on the breadth of the earth, and compassed the camp of the saints about, and the beloved city: and fire came down from God out of heaven, and devoured them.
Rev 20:12 And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works.
Rev 20:14 And death and hell were cast into the lake of fire. This is the second death.