A Troubled Time

Yes. But the passage doesn't say what you ask. Everlasting righteousness was achieved in the obedience of Christ. And an end to sin was made in the sense that sacrifice was no longer necessary. So both these things were established in the time of Christ, the effects have become increasingly more evident with the passage of time, and will come to full consummation in eternity.

The 'he' in Daniel 9:27 is Christ himself, not some antichrist. The covenant he established with Israel was the new covenant

To understand, look where Daniel was looking

“in the first year of his reign I Daniel understood by books the number of the years, whereof the word of the LORD came to Jeremiah the prophet, that he would accomplish seventy years in the desolations of Jerusalem. And I set my face unto the Lord God, to seek by prayer and supplications, with fasting, and sackcloth, and ashes:”
‭‭Daniel‬ ‭9:2-3‬ ‭KJV‬‬

after he prays Gabriel shows up to give him understanding of Jeremiah’s prophecies regarding Jerusalem and it’s desolation and temple destruction

I don’t really place it anywhere because they never did what was determined they had seventy “ weeks “ to do . As a response to daniels supplications and prayers for isreal

Did you read Nehemiah 4?

My determination comes from what is in the text. Do you see that the last part of verse 25 is associated with 'restore and to build Jerusalem' in the same verse?

Yes.