It is undoubtedly true that the Book of Daniel, as it comes down to us today, was a second-century-BCE Jewish novel. However, it is no longer accepted that the book was written in its entirety during the Maccabean period. Philip R. Davies says in 'The social world of apocalyptic writings', published in The World of Ancient Israel: Sociological, Anthropological and Political Perspectives (edited by R.E. Clements),page 256, "The view that all of Daniel was composed in the Maccabean period is obsolete: chapters l-6 are widely accepted as not only earlier, but reflecting a different social setting from the visions of Chapters 7-12." Supporting this view is Leonard J Greenspoon, who says in 'Between Alexandria and Antioch: Jews and Judaism in the Hellenistic Period', published in The Oxford History of the Biblical World (edited by Michael D. Coogan), page 341,"The Hebrew form of Daniel neatly divides into two parts: chapters 1 to 6 consist of a collection of tales, in which Daniel and his companions demonstrate the superiority of their God and those who obediently follow him over the worshippers of false, empty and powerless deities." On page 322, Greenspoon describes the Book of Daniel as a Jewish novel.
Although parts of the book are identified as written in the early post-Exilic period, parts are undoubtedly from the second century. Lester L. Grabbe says in Ancient Israel: What Do We Know and How Do We Know It?, page 211:
As for Daniel, the writer seems to know of Nebuchadnezzar only through the biblical text. The siege of Jerusalem in Jehoiakim's third year is based on a partial misunderstanding of 2 Chronicles. The other stories in Daniel about Nebuchadnezzar seem at least in part based on legends rising out of the reign of Nabonidus. This was first recognized by W. von Soden (1935) but confirmed in a startling way by the discovery of of 4Q Prayer of Nabonidus.[This Dead Sea Scroll text is intermediate between the earlier, Babylonian account and the Book of Daniel.]
A very clear historical error is to be found the account of the Persian conquest of Babylon, in Daniel 5:31: "
And Darius the Median took the kingdom, being about threescore and two years old." It was Cyrus the Great who conquered Babylon. Darius I was a successor who followed Cyrus somewhat later, but Daniel 6:28 places Cyrus after Darius. An error in respect to Belshazzar is explained by the Jewish Encyclopedia:
The following important differences between Belsharusur and the Belshazzar of Daniel are patent. The former was the son of the last king of Babylon [Nabonidus], but never reigned, except possibly as coregent with his father; while the latter is distinctly called the last king and the son of Nebuchadnezzar, both of which statements are undoubtedly made in perfectly good faith by the author of Daniel.
This means at least that the earliest author was not alive at the time of the events portrayed. The book contains historical errors, such that it is unlikely to have been written by a contemporary familiar with the events of the Exile, and the prophecies of the immediate future are less accurate than the prophecies of the period immediately prior to 167 BCE, at which point the book stops inexplicably - unless this is when Daniel was written.
If as Greenspoon and many others conclude, Daniel was a work of fiction, it could not contain prophecies. This means that Daniel's description of the statue in Nebuchadnezzar's dream could not represent kingdoms all the way down to the Christian era, thus a prophecy of Jesus. A more straightforward interpretation, , without any prophetic assumption, is that the feet of clay represented the two Hellenic kingdoms that existed in Syria and Egypt at the time of writing, which would place the completion of the book in the Hellenic era.