This prophecy is in Daniel 9 v 24 to 27.
The first verse tells us what the prophecy is all about:
24 “Seventy weeks are decreed on your people and on your holy city, to finish disobedience, and to make an end of sins, and to make reconciliation for iniquity, and to bring in everlasting righteousness, and to seal up vision and prophecy, and to anoint the most holy.
God tells Daniel that during a seventy weeks period God’s plan to enable sins to be forgiven will be complete. 70 weeks are literally “units of seven” indicating 490 years.
The next verse gives us more detail:
25 “Know therefore and discern that from the going out of the commandment to restore and to build Jerusalem to the Anointed One, the prince, will be seven weeks and sixty-two weeks. It will be built again, with street and moat, even in troubled times.
Daniel is told that from a decree to rebuild Jerusalem to the Anointed One (or Christ) will be 7 + 62 weeks, that is 69 x 7 = 483 years.
There were four decrees involved in the rebuilding of Jerusalem:
The first is recorded in Ezra 1 (approx. BC 540). Cyrus king of Persia authorized the Jews to return to Jerusalem and rebuild the house of the LORD God of Israel:
1 Now in the first year of Cyrus king of Persia, that the LORD’s word by Jeremiah’s mouth might be accomplished, the LORD stirred up the spirit of Cyrus king of Persia, so that he made a proclamation throughout all his kingdom, and put it also in writing, saying, 2 “Cyrus king of Persia says, ‘The LORD, the God of heaven, has given me all the kingdoms of the earth; and he has commanded me to build him a house in Jerusalem, which is in Judah. 3 Whoever there is amongst you of all his people, may his God be with him, and let him go up to Jerusalem, which is in Judah, and build the house of the LORD, the God of Israel (he is God), which is in Jerusalem.
The second is recorded in Ezra 6 (approx. BC 522). Darius king of Persia enforced the earlier decree of Cyrus:
7 Leave the work of this house of God alone; let the governor of the Jews and the elders of the Jews build this house of God in its place. 8 Moreover I make a decree what you shall do for these elders of the Jews for the building of this house of God: that of the king’s goods, even of the tribute beyond the River, expenses must be given with all diligence to these men, that they not be hindered.
The third is recorded in Ezra 7 (approx. BC 469). Artaxerxes king of Persia issued a decree encouraging Jews to return to Jerusalem:
12 Artaxerxes, king of kings,
To Ezra the priest, the scribe of the law of the perfect God of heaven.
Now 13 I make a decree, that all those of the people of Israel, and their priests and the Levites, in my realm, who intend of their own free will to go to Jerusalem, go with you.
The fourth is recorded in Nehemiah 2 (approx. BC 456). Artaxerxes authorized materials for building the gates and walls of Jerusalem:
7 Moreover I said to the king, “If it pleases the king, let letters be given me to the governors beyond the River, that they may let me pass through until I come to Judah; 8 and a letter to Asaph the keeper of the king’s forest, that he may give me timber to make beams for the gates of the citadel by the temple, for the wall of the city, and for the house that I will occupy.”
The king granted my requests, because of the good hand of my God on me.
Daniel was being told that Christ could be expected 483 years from somewhere between BC 540 to 456 ie. BC 57 to AD 27.
The next verse in the prophecy gives us more detail:
26 After the sixty-two weeks the Anointed One will be cut off, and will have nothing. The people of the prince who come will destroy the city and the sanctuary. Its end will be with a flood, and war will be even to the end. Desolations are determined.
The Anointed One (Christ) will be cut off after the 69 weeks. Christ was to be crucified by approx. AD 27.
The rest of the prophecy appears to relate to AD70 and the destruction of the temple in Jerusalem