Angel,
You asked about Daniel's "Seventy Weeks" prophecy. (Dan. 9:24-27) Now I suspect you were just expressing your concern with OBVES' crazy number juggling, in which he uses this prophecy to somehow come up with various dates for the end of the world. Actually, as all serious students of scripture will tell you, Daniel's "Seventy Weeks" prophecy pointed to the time of Christ's first coming, not to the time of his second coming. If, however, you are really interested in Daniels "Seventy Weeks" prophecy, I think you may find the following information interesting.
Daniel's "Seventy Weeks"
The Watchtower Society insists, against the testimony of all historians, that Artaxerxes came to the throne of Persia in 474 BC. They do so to support their interpretation of Daniel's 70 weeks prophecy. (Dan.9:24-27) They say, "Since Daniel prophesied that 69 weeks (of years) would pass between the issuing of a decree to rebuild Jerusalem and the coming of the Messiah, that decree must have been given 483 years before 29 AD, the year of Christ's baptism. And because 483 years before 29 AD was the year 455 BC, 455 BC must have been the 20th year of Artaxerxes, the year in which the Bible tells us such a decree was issued." (Neh. chapter 2 )
However, all serious historians now assure us that Artaxerxes' 20th year of ruling Persia took place in 445 BC, not in 455 BC as the Watchtower Society says. How can this problem be resolved and Daniel's "Seventy Weeks" prophecy be understood? To me the solution seems easy enough. For I am convinced that Nehemiah did not return to Jerusalem and give his command to begin rebuilding that city until the year 440 BC, even though he had been granted permission by Artaxerxes to issue such a command five years earlier, in Artaxerxes' 20th year as king of Persia, which historians assure us took place in 445 BC. (Neh. 1:1-6)
Why do I believe this? Because the first century Jewish historian tells us that Nehemiah "came to Jerusalem" not "in the twentieth year of Artaxerxes" as the Bible seems to say, but in his "twenty and fifth year." (Ant. XI, 5, 7) The fact is that the Bible does not actually say that Nehemiah returned to Jerusalem in Artaxerxes' 20th year. It only tells us that Artaxerxes then gave Nehemiah permission to do so. While Josephus, on the other hand, tells us of the time that Nehemiah actually "came to Jerusalem."
Concerning this matter, in his book, "History Of Israel" (third edition, 1981, pg. 381) John Bright tells us, "The Bible gives us the impression that Nehemiah set out at once, accompanied by a military escort (Neh.2:9). But Josephus (Ant. XI, 5, 7), who follows the Septuagint text, the first part of which is preserved in 1 Esdres, places his arrival only in 440. Though assurance is impossible, this may be correct. If Nehemiah first went to Babylon and collected Jews to accompany him, as Josephus has it, and then having presented his credentials to the satrap of Abah-nahara, attended to the procurement of building materials before proceeding to Jerusalem, as he possibly did since work was begun soon after his arrival, the date is not unreasonable."
Other scholars agree with Bright's assessment of Josephus' probable accuracy in this matter. For instance, Sigmund Mowinckel, a highly regarded Scandinavian bible scholar, believes that Josephus used a separate Greek version of Nehemiah that in several respects differed from that preserved in the LXX. He argues that Josephus' chronological information on the Persian kings was not his own calculations or mistakes, but was quoting from this now lost Greek version of Nehemiah. On Josephus' statement about the 25th year of Artaxerxes, Mowinckel says that his figures may very well be the original ones. He writes, "In my opinion the balance [of evidence] is in favor of [the figure] '25'." (Vol. 3, p.45 of Studien zu dem Buche Ezra-Nehema, Vols. 1-3, Oslo, 1964)
But how does the fact that Nehemiah did not give his order to begin rebuilding Jerusalem until 440 BC help us to make sense of Daniel's "Seventy Weeks" prophecy? As most students of Bible prophecy know, Daniel's "seventy weeks" are generally understood as referring to seventy weeks of years (seventy sets of seven years) totaling a period of 490 solar years. But the Jews used a lunar calendar! Their years were lunar years, not solar years. And, despite the fact that the Jews adjusted their lunar calendars by adding a thirteenth month to them every few years to prevent them from falling too far out of sync with the solar year, the fact remains that a "year" to the Jews always meant a lunar year, not a solar year. And a week of years to the Jews would have meant seven lunar years. And seventy weeks of years to the Jews would have meant 490 lunar years, not 490 solar years.
Now, since one lunar year contains 354.367 days, 490 lunar years contain 173,639.83 days. And 173,639.83 days divided by 365.2425 (the number of days in a solar year) equal 475.40 solar years. With these things in mind, I have come to conclusion that Daniel's "seventy weeks" were a period of 475.4 years which ran from 440 BC to 36 AD. I believe those 475.4 years began at the time Nehemiah gave his "commandment to restore and to build Jerusalem" (Dan. 9:25 KJV; Neh. 2:17,18). And I believe those 475.4 years ended at the time God acted to "confirm the [new] covenant with many" by pouring His Holy Spirit out on Gentiles for the first time (Dan. 9:27 KJV; Acts 10). I believe the "many" here referred to were the "many nations" God promised Abraham that he would one day become the father of. (Gen. 17:4) Thus, I see no need to rewrite history, as the Watchtower Society does, in order to understand Daniel's "70 weeks" prophecy.
For the facts of history, together with a knowledge that the Jews used a lunar calendar, combine to show that, just as Daniel prophesied, the Messiah appeared in the fall of the year 29 AD. At that time Jesus Christ was "cut off" from his people and, quite literally, "had nothing for himself." (Dan.9:26) For he then began a forty day long fast in the wilderness. Then, after three and a half years, in the middle of Daniel's seventieth week, Christ's sacrificial death brought an end to the Jewish system of sacrificial offerings.(Dan. 9:27) Finally, three and a half years later, at the end of Daniel's "Seventy Weeks" Christ "confirmed a covenant with many" (Dan.9:27) when he, for the first time, poured out his Holy Spirit on non-Jewish people. This confirmed the fact that God intended for the good news of Jesus Christ to be preached to all people on earth, just as Christ said that it would be. (Math. 24:14)