The date of the returning captive Jews has nothing to do with the reign of Artaxerxes as is presently assumed by so many. The return of the Jews to their homeland has to do with the first year Cyrus conquered Babylon, not the first year he reigned over Persia, but the first year he conquered Babylon where the Jews were held captive. According to history this was cir. 536 BC. However, this date is fixed by historians who receive Claudius Ptolemy’s seven eclipses between the dates of 747 BC and 330 BC to date historical events during this period. Ptolemy’s work has been nearly universally accepted by modern historians for the last 400 years. Nevertheless, astronomers have been finding fault with his works for almost 1000 years, not to mention that some prominent contemporary historians, such as Plutarch, were never impressed with dating historical events through astronomical observations and calculations. Therefore, although I cannot prove that Cyrus conquered Babylon in 457 BC, 79 years after the normally accepted date set by Ptolemy (536 BC), but neither can modern historians prove otherwise without using Claudius Ptolemy’s alleged infallible conclusions.
In Ezra 1:2 we see that Zerubbabel, heir to the throne of king Solomon, returned to Jerusalem leading a company of Israelites in the first year of Cyrus, King of Persia (Ezra 1:1-5). Cyrus released the captive Jews, in fulfillment of the word of Jeremiah the prophet (Ezra 1:1), in order that they may build both the Temple and the city (Ezra 1:1-4; cp. Isaiah 44:28; Jeremiah 29:10).
The proclamation or decree to build Jerusalem and the Temple, found in the first chapter of the book of Ezra, is really the only decree of its kind given by any of the four kings referred to in Daniel 10:1 & 11:2 or the entire book of Ezra. The decree given to Ezra by Artaxerxes, king of Persia, in Ezra chapter seven did not contain a command to build anything. Even the decree in Ezra 6 that Darius gave to Tatnai, his governor beyond the river, did not contain a command to build but to refrain from hindering the building that was going on.
The commandment given to Nehemiah is not recorded in God’s word. Nevertheless, the Jewish builders referred to the decree of Cyrus, king of Persia, who commanded that the Temple and Jerusalem be rebuilt, so Darius commanded a search to be made for the document at Babylon (Ezra 6:1-5; cp. 5:11-17). It was Cyrus’ command that made the Jews’ building the Temple and the city walls legal in the eyes of the reigning kings of Persia (Ezra 5:8-17). In fact, the decree made by Artaxerxes in Ezra 6:8-12 served only to enforce the earlier decree given by Cyrus (cp. Ezra 6:3-5). The decrees of the kings of Persia could not be knowingly changed or altered (Daniel 6:8, 15; Esther 1:19). Therefore, the decree of Cyrus is the only real decree given to rebuild Jerusalem and the Temple and must be the commandment mentioned in Daniel 9:25. This decree was given 51 years after the Jews went into captivity, and after 70 years of servitude to Babylon.
 Some students maintain that the children of Israel were at Babylon for the full 70 years. I don’t agree. I believe the 70 years concern the Jews servitude to Babylon and include the 19 years in the land (cp. 2Kings 24:1 & Jeremiah 25: 1, 11 with 2Kings 25:8; Jeremiah 52:12) and another 51 as captives in the precincts of Babylon. The argument that the Jews spent 70 years in Babylon stems from the idea that the people will be absent from the land while the land is desolate (Leviticus 26:34, 43). This may be true, but Ezra 3:10-12 seems to argue that there were ‘many’ priests who remembered Solomon’s Temple and wept upon rebuilding the foundation of the new Temple in the second year after their return from captivity. This would mean a 10-year-old Levite taken into captivity would have been 63 when the new foundations were built with a 51 year absence from the land. If the Jews were 70 years in Babylon, the same Levite must have been 82 years old. This is possible, but to say there were ‘many’ seems to me to be a stretch. Later when the Temple was nearly finished, Haggai asked if there were any in the land who remembered Solomon’s Temple (Haggai 2:3). This same 10-year old would have been approximately 103 years old if the Jews spent 51 years in Babylon but 122 if he spent 70 years in captivity. This would be possible for the former, but highly unlikely for the later. Therefore, I conclude that the 70 years of servitude must include 19 years in the Jews’ own land and 51 years in captivity in Babylon.