There's a wealth of evidence that the 'prophecies' in Daniel were indeed written well after the events that they were supposed to have 'predicted'.
On a very very basic level, we have no text of Daniel that can be dated to earlier than the 2nd century BCE.
The we have the fact that the book is never mentioed in any extant Jewish literature before the 2nd century BCE.
We have the fact that the book wasn't added to the Jewish canon until 90 CE, it was not included in the earlier canon that was closed c. 2nd century BCE.
We have a host of historical inaccuracies, which only improve the closer we get to the 2nd century BCE. If the book was written by someone living in the 6th century BCE we would expect the author not to have made som many historical errors, for example, it wouldn't be too much to ask for him to at least get the succession of Babylonian rulers.
The reference to 'Chaldean' as another word for 'Soothsayer' is another clue as 'Chaldean' was never used in this context until the 2nd century BCE.
The book was written by more than one person, one scholar thinks there may be as many as nine authors.
Ecclesiastes, written about 180 BCE, does not include Daniel in its list of great Israelites.
Chapter 8 doesn't really make much sense if written in the 6th century BCE. The author(s) cannot make up there mind(s) when the cessation of daily sacrifices are to stop. It starts in 8:14 with 2,300 mornings and evenings (3 years, 35 days), but in 7:25 it is given as 3 1/2 years, in 9:27 it is 3 1/2 years, in 12:11 it is 1,290 days but in the very next verse it is 1,335 days.
12: 11 "From the time that the daily sacrifice is abolished and the abomination that causes desolation is set up, there will be 1,290 days.
12:12 Blessed is the one who waits for and reaches the end of the 1,335 days.
It is a complete mess, and best explained by recognising that the writer(s) must have been writing during the reign of Antiochus and really didn't know when the 'Abomination that makes Desolate' would be finished. The fact that the Zues Olympios is mentioned also points to a late date.
There'e a clear defining line in Daniel between history and prophecy, if we look at 11:22-45 we find a description that fits Antiochus Epiphanes. The demarcation can be found at verse 40, where a third campaign against Egypt is recorded, however there was no third campaign. Daniel also claims that Antiochus will die in Palestine, but we know he died in the east in Iran. Thus, it looks as if Daniel was written about 166-165 BCE, because that is where historical facts relating to the 2nd century BCE go askew.
There's far more to discuss, such as the host of later interpolations into the text, but I couldn't get a simple answer to my very first question, so much of the debate was worthless.
If Starman was able to have a civil debate, then we could have discussed a whole range of issues.
But, even this cursory summary, and the complete lack of evidence for the text existing before the 2nd century BCE, does not help the 6th century BCE guys, and the biggest condemnation is that the main prophecy of Daniel failed.
The pro-6th century BCE guys on this thread have actually shown nothing except religious fervour in support of their 6th century BCE date. Starman, in particular, takes a very naive approach to the composition of the biblical texts, which is fine, he is fully entitled to do that. However, he shouldn't get upset when he discovers that this approach doesn't merit much of a response from people who have studied the Bible at a high academic level.