'King' in the Bible

In the second year of Darius the king, in the sixth month, on the first day of the month, came the word of the Lord by Haggai the prophet to Zerubbabel, the son of Shealtiel, ruler of Judah, and to Joshua, the son of Jehozadak, the high priest, saying,

On the twenty-fourth day of the month, in the sixth month, in the second year of Darius the king.