Ancient scholars as diverse as Josephus (37 A.D. – 100 A.D.) and Jerome (347 A.D. – 420 A.D.) agree that the book of Daniel was written contemporaneously with the events that it describes in Babylon 2,600 years ago

The earliest interpreters of Daniel to whom we have access are the writers of the New Testament (cf. specifically Matt. 24:15) and Josephus (AD 37 – post. 100). Josephus regards Daniel as ‘one of the greatest prophets’ who ‘was not only wont to prophesy future things, as did the other prophets, but he also fixed the time at which these would come to pass.’ In his summary of Daniel 11-12, Josephus comments, ‘And these misfortunes our nation did in fact come to experience under Antiochus Epiphanes, just as Daniel many years before saw and wrote that they would happen.’ Countering the viewpoint of the Epicureans, who denied that any wise being directed human affairs, Josephus argued that if they were right ‘we should not have seen all these things happen in accordance with his prophecy’. There is no evidence at this period of any doubt about the historicity of the sixth-century Daniel, nor of the genuineness of his prophecy.

… Jerome (c. 345 – c. 419), however, is the best known (early Christian commentator on Daniel). His commentary was intended to refute an attack on the historicity of Daniel by the Neoplatonist Porphyry (232 – c. 305), who, as we know from Jerome, considered the prophetic passages in Daniel to be the narration of an unknown author during the time of Antiochus Epiphanes. This conclusion he reached from the premise that the author could not have known the future. If it had not been for the careful quotations by Jerome the work of Porphyry would not have survived, and it is ironical that at the present time it is the position of Porphyry and not that of the Christian apologist which dominates most works of scholarship. In the early centuries of the Christian era Christians accepted without question the authenticity of Daniel and his prophecy.

Josephus, writing his account of the destruction of Jerusalem, made allusion to a double application of Daniel 9:27. Having pointed out that Daniel wrote of the nation’s sufferings under Antiochus Epiphanes, he went on: ‘In the very same manner Daniel also wrote concerning the Roman government, and that our country should be made desolate by them.’ His interpretation of the fall of Jerusalem as the ending of the seventy sevens of Daniel became standard Jewish teaching, and passed into Christian exegesis. Only at the end of the second century did Christian scholars begin to compute the seventy sevens so as to make them terminate in the coming of Christ. There were many variations in detail; three and a half sevens was often vaguely related to the period of the Antichrist. The influence of Jerome’s translation of ‘an anointed one, a prince’ (9:25), ‘ad Christum ducem’, continues in the margin of JB (Jerusalem Bible), ‘or Prince Messiah’. This messianic interpretation is still popular and is represented by the commentaries of Pusey, C.H.H. Wright and E.J. Young. It is adopted in a modified form in this commentary.

Source: Joyce G. Baldwin, Daniel: An Introduction and Commentary (Tyndale Old Testament Commentary Series). Downers Grove: Intervarsity Press, 1978, pages 70, 71, 194-195.

Jesus Christ to his disciples:

“So when you see standing in the holy place ‘the abomination that causes desolation,’ spoken of through the prophet Daniel—let the reader understand— then let those who are in Judea flee to the mountains.” (Mt 24:15)

Jesus Christ citing Daniel 7:13 to the High Priest who asked Him to testify to the Sanhedrin whether He was the Messiah, the Son of God:

“You have said so,” Jesus replied. “But I say to all of you: From now on you will see the Son of Man sitting at the right hand of the Mighty One and coming on the clouds of heaven.” (Mt 26:64)