Zephaniah reveals that only the judgment of God can cleanse Judah of the sins that she has committed. The day of the Lord is coming and the nation must prepare for its salvation. According to the genealogy at the beginning of the book, Zephaniah was active during the reign of King Josiah.

Zephaniah 1

1:1 The word of the LORD which came unto Zephaniah the son of Cushi, the son of Gedaliah, the son of Amariah, the son of Hizkiah, in the days of Josiah the son of Amon, king of Judah.