There have been some partial quotations of Josephus on this board recently in relation to how he explained the '70 Years'.
In the interests of scholastic honesty and so that his words are not taken out of context, here are some relevant passages with their context. You might ask yourself, do the 70 Years (as spoken by the Prophet Jeremiah) begin with the destruction of the temple or before the destruction of the temple? Was the temple destroyed during a 70 year period or was it desolated at the beginning the 70 year period described by Jeremiah?
Whatever Josephus says, he is not the final authority. However, the Society and others have a habit of using certain quotes from him out of context.
Josephus Antiquities 10.7.3:
3. Now when Zedekiah had preserved the league of mutual assistance he had made with the Babylonians for eight years, he brake it, and revolted to the Egyptians, in hopes, by their assistance, of overcoming the Babylonians. When the king of Babylon knew this, he made war against him: he laid his country waste, and took his fortified towns, and came to the city Jerusalem itself to besiege it. But when the king of Egypt heard what circumstances Zedekiah his ally was in, he took a great army with him, and came into Judea, as if he would raise the siege; upon which the king of Babylon departed from Jerusalem, and met the Egyptians, and joined battle with them, and beat them; and when he had put them to flight, he pursued them, and drove them out of all Syria. Now as soon as the king of Babylon was departed from Jerusalem, the false prophets deceived Zedekiah, and said that the king of Babylon would not any more make war against him or his people, nor remove them out of their own country into Babylon; and that those then in captivity would return, with all those vessels of the temple of which the king of Babylon had despoiled that temple. But Jeremiah came among them, and prophesied what contradicted those predictions, and what proved to be true, that they did ill, and deluded the king; that the Egyptians would be of no advantage to them, but that the king of Babylon would renew the war against Jerusalem, and besiege it again, and would destroy the people by famine, and carry away those that remained into captivity, and would take away what they had as spoils, and would carry off those riches that were in the temple; nay, that, besides this, he would burn it, and utterly overthrow the city, and that they should serve him and his posterity seventy years; that then the Persians and the Medes should put an end to their servitude, and overthrow the Babylonians; "and that we shall be dismissed, and return to this land, and rebuild the temple, and restore Jerusalem." When Jeremiah said this, the greater part believed him; but the rulers, and those that were wicked, despised him, as one disordered in his senses. Now he had resolved to go elsewhere, to his own country, which was called Anathoth, and was twenty furlongs distant from Jerusalem; and as he was going, one of the rulers met him, and seized upon him, and accused him falsely, as though he were going as a deserter to the Babylonians; but Jeremiah said that he accused him falsely, and added, that he was only going to his own country; but the other would not believe him, but seized upon him, and led him away to the rulers, and laid an accusation against him, under whom he endured all sorts of torments and tortures, and was reserved to be punished; and this was the condition he was in for some time, while he suffered what I have already described unjustly.