When was the book of Daniel written? The sixth century or the second?

The passages

In the third year of the reign of Jehoiakim king of Judah came Nebuchadnezzar king of Babylon unto Jerusalem, and besieged it.

Daniel 1:1

And Darius the Median took the kingdom, being about threescore and two years old.

Daniel 5:31

And in his estate shall stand up a vile person, to whom they shall not give the honour of the kingdom: but he shall come in peaceably, and obtain the kingdom by flatteries.

Daniel 11:21

The problem

Three things make scholars question the traditional date. First, the history. Daniel 1:1 places Nebuchadnezzar's siege in Jehoiakim's third year, which does not match Jeremiah 25:1 or 46:2. Belshazzar is called king and Nebuchadnezzar's son, while Babylonian records show he was the son of Nabonidus and never formally king. "Darius the Mede" is not known from any other source. Second, the language: parts are in Aramaic, and the book contains Persian and Greek loanwords, including names of musical instruments. Third, the visions in chapters 8 and 11 give a detailed account of events down to Antiochus IV Epiphanes (167–164 BC), and then they cease to match later history. Chapter 11 predicts his death in Palestine, and he died in Persia.

If the book was written in the second century, the predictions to that point are after the fact.

What believers and scholars say

Sixth-century date. Conservative scholars such as Archer, Baldwin and Kitchen argue that the Aramaic is compatible with an early date, that Daniel was well informed about Babylonian court life, and that Belshazzar's role as co-regent explains the title. "Darius the Mede" has been identified with Gubaru or with Cyrus under another name. Jesus refers to "Daniel the prophet" (Matthew 24:15), which is taken to support authenticity.

Second-century date. Collins and most critical scholars hold that the book was written during the Maccabean crisis, using older stories about a wise Daniel. The accurate history up to 165 BC and the vague account after it is the central evidence. In this view the book is meant to encourage Jews in persecution, and the prophetic form is a literary convention.

Composite book. Some propose that the stories of chapters 1–6 are older than the visions in chapters 7–12, which would explain the differences of tone.

Where this leaves it

The date affects whether Daniel contains prediction or retrospect. The evidence of the language and of the history is not conclusive, but it has persuaded most scholars outside conservative traditions. Those who hold the early date have answers to each objection, and those who hold the late one say the answers pile up.