History points the date of the decree to restore and rebuild Jerusalem, and scripture tells us.
Ezra 7:11-21
11 Now this is the copy of the letter that the king Artaxerxes gave unto Ezra the priest, the scribe, even a scribe of the words of the commandments of the Lord, and of his statutes to Israel.
12 Artaxerxes, king of kings, unto Ezra the priest, a scribe of the law of the God of heaven, perfect peace, and at such a time.
13 I make a decree, that all they of the people of Israel, and of his priests and Levites, in my realm, which are minded of their own freewill to go up to Jerusalem, go with thee.
14 Forasmuch as thou art sent of the king, and of his seven counsellors, to enquire concerning Judah and Jerusalem, according to the law of thy God which is in thine hand;
15 And to carry the silver and gold, which the king and his counsellors have freely offered unto the God of Israel, whose habitation is in Jerusalem,
16 And all the silver and gold that thou canst find in all the province of Babylon, with the freewill offering of the people, and of the priests, offering willingly for the house of their God which is in Jerusalem:
17 That thou mayest buy speedily with this money bullocks, rams, lambs, with their meat offerings and their drink offerings, and offer them upon the altar of the house of your God which is in Jerusalem.
18 And whatsoever shall seem good to thee, and to thy brethren, to do with the rest of the silver and the gold, that do after the will of your God.
19 The vessels also that are given thee for the service of the house of thy God, those deliver thou before the God of Jerusalem.
20 And whatsoever more shall be needful for the house of thy God, which thou shalt have occasion to bestow, bestow it out of the king's treasure house.
21 And I, even I Artaxerxes the king, do make a decree to all the treasurers which are beyond the river, that whatsoever Ezra the priest, the scribe of the law of the God of heaven, shall require of you, it be done speedily,
"The third “decree” in Ezra is that of Artaxerxes in Ezra 7:11-28. This is a decree to actually rebuild the city. The decree comes from the seventh year of Artaxerxes (Ezra 7:8). This is somewhere around 458 BC from what we know of Artaxerxes’ reign from outside sources. This decree actually resulted in the rebuilding of Jerusalem under Nehemiah."
http://evidenceforchristianity.org/...tore-and-rebuild-jerusalem-issued-daniel-925/
So this timeline of Daniel 9 presents the 490 years as an uninterrupted period with the beginning of the 70 weeks "from the time the word goes out to rebuild and restore Jerusalem," of Daniel 9:25 with the decree by Artaxerxes I in 458/7 BCE which provided money for rebuilding the temple and Jerusalem and allowed for restoration of a Jewish administration. It ends 3½ years after the crucifixion, and has the appearance of "Messiah the Prince" at the end of the 69 weeks (483 years) which is aligned with Jesus' baptism in 27 CE, in the fifteenth year of Tiberius Caesar.
The 'cutting off' of the "anointed one" refers to the crucifixion 3½ years after the end of the 483 years, bringing "atonement for iniquity" and "everlasting righteousness". Jesus is said to 'confirm' the "covenant" between God and mankind by his death on the cross "in the midst of" the last seven years. At the moment of his death the thick curtain between the Holy and Most Holy Places in the Temple ripped from top to bottom, marking the end of the Temple's sacrificial system. The last week ends 3½ years after the crucifixion in 34 CE, when the gospel was redirected from only the Jews to all peoples.
So it shows how a prophetic day represents a literal year, with the 70 weeks of Daniel, broken down to number of days (70 x 7) or 490 days, which then equate to a literal 490 years of the prophecy.