“Nebuchadnezzar king of Babylon came to Jerusalem and besieged it . . . The king said . . . to bring some of sons of Israel . . . to stand in the king’s palace . . . and teach them the literature and tongue of the Chaldeans . .  . that they should be educated three years, at the end of which they were to stand before the king” (Daniel 1:2-5 LSB). Critics claim that the “three years” of Daniel 1:5 of educational training that Daniel and his three Hebrew companions received after coming to Babylon as captives conflict with their reported appearance, “before Nebuchadnezzar . . . in service before the king” by “the second year of the reign of Nebuchadnezzar” (Daniel 1:18,19; 2:1 LSB), since Nebuchadnezzar is called “king of Babylon” at the time of the capture of the Jews. They claim that the Bible’s account is fictional because it reports the three years of training as completed in only the second year of Nebuchadnezzar’s reign.

In Daniel’s time, the Babylonians and the Medo-Persians , not the Jews, used the accession year system in counting kings regnal years. The Babylonian calendar  years ran from New Year’s Day on Nisan 1 in early spring to the next Nisan 1. When a king came to power, his reign, or first regnal year, did not officially start until the next Nisan 1. The months he reigned as king prior to that next Nisan 1 was called his accession year. The Jews of the kingdom of Judah used the non-accession year method of reckoning the years of a king’s reign, which meant the king’s accession year counted as the first year of his reign,
We can see this difference in counting the tears of a king’s reign by a comparison of Daniel 1:1 with Jeremiah 25:1 and 46:1:
“In the third year of the reign of Jehoiakim king of Judah, Nebuchadnezzar king of Babylon came to Jerusalem and besieged it” (Daniel 1:1 LSB).
Daniel, writing in Babylon, used the Babylonian accession-year system.
” . . . in the fourth year of Jehoiakim the son of Josiah, the king of Judah (that was the first year of Nebuchadnezzar king of Babylon” (Jeremiah 25:1 LSB).
“Concerning the military force of Pharaoh Neco king of Egypt, which was by the Euphrates River at Carchemish, which Nebuchadnezzar king of Babylon struck down in the fourth year of Jehoiakim the son of Josiah, king of Judah” (Jeremiah 46:1 LSB).
Jeremiah, writing in Jerusalem, used the Jewish non accession-year reckoning.
So, by the Babylonian accession-year reckoning, Nebuchadnezzar’s accession year was the 3rd year of Jehoiaakim, but by Jewish non accession-year reckoning it was the 4th year of Jehoiakim.

Daniel and his companions’ were “educated three years” (Daniel 1:5 LSB). Nebuchanezzar’s accession year, was year 1, “the first year of the reign of Nebuchadnezzar” (Jeremiah 25:1 LSB) was year 2, and “the second year of the reign of Nebuchadnezzar” (Daniel 2:1 LSB) was year 3.

The Biblical and historical facts thus prove that there is no contradiction between Daniel 1:5 and Daniel 2:1. This is because, “no prophecy of scripture ever came through human will; but rather human beings moved by the holy Spirit spoke under the influence of God” (2 Peter 1:21 NAB), “who has perfect knowledge” (Job 36:4 NIV), “who does not lie” (Titus 1:2 NAB).