Haggai (Aggée) 1:1 (ESV)

1 In the second year of Darius the king, in the sixth month, on the first day of the month, the word of the LORD came by the hand of Haggai the prophet to Zerubbabel the son of Shealtiel, governor of Judah, and to Joshua the son of Jehozadak, the high priest:

The Persian king named here is Darius I (522-486 BC), not the earlier Darius the Mede (Daniel 5:31; Daniel 6:1, Daniel 6:6, Daniel 6:9) or the later Darius II Nothus (Nehemiah 12:12).