Haggai in Fausset's Bible Dictionary

("my feast".) A name given in anticipation of the joyous return from exile. Perhaps a Levite, as the rabbis say he was buried at Jerusalem among the priests. Tradition represents him as returning with the first exiles from Babylon his birthplace, under Zerubbabel 536 B.C., when Cyrus, actuated by Isaiah's prophecies concerning himself (Isaiah 44:28; Isaiah 45:1), decreed the Jews' restoration and the rebuilding of the temple, for which he furnished all necessaries. (See CYRUS; EZRA; AHASUERUS; ARTAXERXES; DARIUS.) In spite of Samaritan opposition the temple building went on under Cyrus and Cambyses (Ahasuerus Ezra 4:6); but under the Magian usurper Smerdis (Artaxerxes Ezra 4:7-23) the Samaritans procured a royal decree suspending the work. Hence, the Jews became so indifferent about it that when Darius came to the throne (521 B.C.), whose accession virtually nullified the usurper's prohibition, they pretended that as the prophecy of the 70 years applied to the temple as well as to the captivity in Babylon (Haggai 1:2), they were only in the 68th year, and that, the time not yet having come, they might build splendid cieled mansions for themselves. Haggai first, and Zechariah two months later, were commissioned by Jehovah (Haggai 1:1) in Darius' (Hystaspes) second year, 520 B.C., to rouse them from their selfishness to resume the work which had been suspended for 14 years. The dates of his four distinct prophecies are given. I. (Haggai 1). On the first day of the 6th month of Darius' second year of reigning, 520 B.C. Reproves their apathy in leaving the temple in ruins; reminds them of their ill fortune because of their neglect of God's house. In consequence, within 24 days they began building under Zerubbabel (Haggai 1:12-15)...

Link: https://bible-history.com/faussets/H/Haggai/