If you study Daniel’s prophecy of Seventy Weeks, you need to consider not only the prophecy’s structure (covenantal redemption) and chronological value (weeks of years), as per our previous posts, but also the starting point for the beginning of the weeks.
When do the Seventy Weeks begin? This will determine when they end. They begin at a certain “command,” according to Daniel 9:25.
The “command” in Daniel 9:25 and reads: “Know therefore and understand, that from the going forth of the command to restore and build Jerusalem.” Initially, it would seem to refer to Cyrus’ decree to rebuild the temple in 538 BC. This command appears in 2 Chronicles 36:22–23 and in Ezra 1:1–4; 5:13, 17, 6:3. This is a vitally important decree impacting Israel’s history as she returns from the Babylonian captivity.
But this prophecy does not seem to start with Cyrus’ decree, as famous and as significant as it is. After all, Daniel specifically speaks of the command to “restore and build Jerusalem.” This is an important qualification to which we must give attention. 
Though Israel attempts half-hearted efforts to rebuild Jerusalem after Cyrus’ decree, for a long time Jerusalem remains a sparsely populated, unwalled village. But Daniel speaks of the command to “restore” (shub, return) Jerusalem (Dan 9:25). This requires that it be returned to its original integrity and grandeur “as at the first” (Jer 33:7). It was not until the middle of the fifth century BC that this is undertaken seriously. 
References decades after Cyrus’s decree, make abundantly clear that little was done toward rebuilding Jerusalem. Nehemiah laments that Jerusalem’s walls are “broken down” (Neh. 1:3; 2:3-5, 17; 7:4). Zechariah speaks of Jerusalem as “destroyed” in his day (Zech. 14:11), even mentioning its soon-coming rebuilding (Zech. 1:16). The enemies of the Jews warn Artaxerxes that the Jews will become a problem if they rebuild the city (Ezra 4:12-23). This explains why Ezra mentions Jerusalem’s utter affliction “even to this day” (Ezra 9:7-9, 15).
Consequently, the decree of Ezra in 457 B.C. during the seventh year of Artaxerxes I (454-424 BC), seems the best possibility. The process of diligent rebuilding climaxes in Jerusalem’s restoration. This process probably begins either in seed during the spiritual revival under Ezra (Ezra 7) or in actuality under the administration of Nehemiah (Neh. 2:1, 17-18; 6:15-16; 12:43). Several political commands prepare for the restoring of Jerusalem, as well as one divine command: “So the elders of the Jews built, and they prospered through the prophesying of Haggai the prophet and Zechariah the son of Iddo. And they built and finished it, according to the commandment of the God of Israel, and according to the command of Cyrus, Darius, and Artaxerxes king of Persia” (Ezra 6:14).
Now then, what are the three periods into which the Seventy Weeks are divided?
The first period of seven weeks must indicate something, for it is set off from the two other periods. Were it not significant Daniel could speak of the sixty-nine weeks, rather than the “seven weeks and sixty-two weeks” (Da 9:25). This seven weeks (or forty-nine years) apparently witnesses the successful conclusion of the rebuilding of Jerusalem. 
The second period of sixty-two weeks extends from the conclusion of Jerusalem’s rebuilding to the introduction of Israel’s Messiah at his baptism when he begins his public ministry (Da 9:25), sometime around AD 26. This interpretation is quite widely agreed upon by conservative scholars, being virtually “universal among Christian exegetes” — excluding dispensationalists. I will deal with the evidence for this terminus more fully in a later post.
The third period of one week is the subject of intense controversy between dispensationalism and other conservative scholarship. I will deal with this key issue in a later post. So please do not “rapture” out of this study and allow there to be “gap” in your eschatological knowledge, otherwise you will feel like one of the “lost tribes.”
 Hengstenberg, Christology of the Old Testament, 2:884ff.
 Hengstenberg, Christology of the Old Testament, 2:884–911. J. B. Payne, Encyclopedia of Biblical Prophecy, 388ff. Charles Boutflower, In and Around the Book of Daniel, 195ff.
 Hengstenberg, Christology of the Old Testament, 2:894ff
 James Montgomery, Daniel, 332.