Much has been written on the Book of Daniel, and on the 70 weeks prophecy, on here. I repost an extract from our revered former Poster Leolaia on this matter.
" 1) This is not a prophecy of "when the Messiah would come", it is an oracle concerned with how long the Temple and the city of Jerusalem would remain in a state of disgrace (culminating with the desolation of the Temple described in the preceding chapter and in ch. 11),
2) There isn't one "messiah" (anointed one, i.e. the high priest of the Temple) but two, with the first arriving at the beginning of the 62 weeks and with the second departing at the end of the 62 weeks,
3) The oracle expands Jeremiah's original 70 years into 490 years on account of the sevenfold "curse" written in the Law of Moses, and the author starts the 490 years with the "word to restore and rebuild" Jerusalem; this indicates that the "word to restore and rebuild" was not sometime later than the putative time of writing (the first year of Darius the Mede) but prior to it, at the start of Jeremiah's seventy years,
4) The "word to restore and rebuild" is in fact a near verbatim allusion to Jeremiah, which contained exactly such a promise by the "word of YHWH" and in v. 2 the author already refers to "the word of YHWH given to Jeremiah the prophet",
5) It is thus not a novel prophecy that Jerusalem and its Temple would be restored but a repetition of Jeremiah's,
6) The 360-day Jewish schematic calendar was fixed to equinoxes and solstices and thus did not lose 5 days a year as your computation requires,
7) There is no reference to crucifixion per se in the oracle,
8) the events you attribute to Titus correspond to the last half-week of the 70 weeks which does not fit into your chronological scheme unless one postpones the 70th week (a contrivance imposed on the text from interpretation),
9) The Christian interpretation also ignores the exact correspondence between the "people of a coming ruler" in the seventy weeks oracle and the "forces of the king of the north" in ch. 11 (which relates to the historical actions of Antiochus IV Epiphanes), and
10) the oracle was most likely written during the Maccabean period (not in 538 BC) as most commentators recognize."