Here are some highlights from Gerhard Hasel’s essay, “The Book of Daniel Confirmed by the Dead Sea Scrolls,” Journal of the Adventist Theological Society 1/2 (1990): 37-49.
“At this juncture we need to make the point that according to current historical-critical opinion with its ‘Maccabean hypothesis,’ the book of Daniel originated in its present form during the time of the Maccabees and the crisis brought about by Antiochus Epiphanes, that is between 168/7 and 165/4 B.C. It seems difficult to believe that such a significant number of Daniel manuscripts would have been preserved in a single desert community, if the book had really been produced at so late a date. The large number of manuscripts can be much better explained if we conclude that the book of Daniel had a much earlier origin.”
“Scholars who theorize that the book of Daniel wasn’t written until the Maccabean crisis (around 165 B.C.) are being compelled to admit that 4QDane [ca. 125 B.C.] comes from ‘only a half century later than the composition of the book of Daniel.’ This means that these scholars will now have to demonstrate that a mere forty or fifty years was sufficient time for all the editorial and other processes needed—according to their traditio-historical and redaction-critical theories—for the book to be developed into its present form and become canonical!”
“In 1969, based on the evidence available at that time regarding the Qumran Daniel texts, Roland K. Harrison concluded that the second-century B.C. dating of the book of Daniel is rendered absolutely impossible by the evidence from Qumran. There was, he said, insufficient time for Maccabean compositions to be circulated, venerated, and accepted as canonical Scripture by a Maccabean sect.”
“There can no longer be any possible reason for considering the book [of Daniel] as a Maccabean product.”
“Ulrich, ‘Daniel Manuscripts from Qumran. Part 1,’ observes that 4QDanc, with its very early dating, ‘is thus, for the Hebrew Bible comparable to the Rylands manuscript of the Johannine Gospel for the New Testament.’ The papyrus fragment of the Gospel of John (published in 1935) known as Rylands 457 and as P52 and dated to the first half of the second century A.D., was made about as few years after John was actually written as 4QDanc was made after Daniel was allegedly written—according to those scholars who insist that Daniel wasn’t written till around 168-165 B.C., during the Maccabean period.”
This evidence inclines me to think that those who persist in dating Daniel to the Maccabean era do so for uncritical, dogmatic reasons. Namely, their religion (historical critical naturalism with its priesthood of archeologists and orthodoxy of unbelief) dictates that they must not believe in a God who inspires predictive prophecy.
At any rate, primary source testimony, manuscript evidence, and historical probabilities are not dictating their conclusions.
 Gerhard F. Hasel, “The Book of Daniel Confirmed by the Dead Sea Scrolls,” Journal of the Adventist Society 1, no. 2 (1990): 40.
 Ibid., 41. Hasel here quotes Eugene Ulrich, “Daniel Manuscripts from Qumran. Part 1,” Bulletin of the American Schools of Oriental Research 268 (1987): 17.
 Hasel, “The Book of Daniel Confirmed by the Dead Sea Scrolls,” 44. Hasel here cites R. K. Harrison, Introduction to the Old Testament (Grand Rapids: Eerdmans, 1969), 1127.
 R. K. Harrison, “Daniel, Book of,” ISBE 1:862. Cited in Hasel, “The Book of Daniel Confirmed by the Dead Sea Scrolls,” 44.
 Ibid., 47–48 n. 27.