Zephaniah is described in vs.1 as the son of Cushi. It is thought that the term Cushi comes from the word Cushite which is to us Ethiopian. We find in this book of the Bible that Ethiopia comes to the Lord, as opposed to being antagonistic which makes me think that Zephaniah's background is from Ethiopia. What would that make him? How about a black Jew. That's not unusual as we see in Acts when Philip runs across an Ethiopian Eunuch who had comes to celebrate God in Jerusalem. So this is fairly common, or at least not uncommon.
As we begin to read Zephaniah we see that the prevalent theme for the book, and the first chapter and the chapters to follow, is the Day of the Lord. If you had any thought of anticipation and looking forward to the day of the Lord, well, maybe you'll have second thoughts after reading this. Aren't we programmed to look forward to the second coming of Christ? Don't we naturally say Maranatha! Come Lord Jesus! But if we say that naturally, then are we taking into account that on this day the following will take place: "I will utterly sweep away everything from the face of the earth." There is no differentiation whether people are righteous or not. There will be a full scale destruction, according to Zephaniah.
Just in case you aren't completely convinced about the tone and the tenor of this Scripture look at vs.15. There is no redeeming value about that day and no hint that if you are righteous or on the side of the Lord then you will be spared the wrath, anguish, ruin and devastation, darkness, gloom, clouds and thick darkness. No one seems to be spared. Just to make sure that we understand that he isn't kidding he finishes it off with: for a full, a terrible end he will make of all the inhabitants of the earth. So, take that for data.