The Day of the Lord on a nation is its just judgment by God: a nation's full accountability to the just and loving God for the nation's sins throughout its history. In the Bible, the Day of the Lord refers to God's just judgment of a nation far more often than to Jesus' return to earth (which also is a good meaning). The Bible shows many examples of His judgment of ancient nations as whole units. National judgments have continued through the centuries after Biblical times, but have become especially common in the last 80 years as nation after nation has come under atheistic communism or another dominating spiritual darkness. As with individuals, a nation that has sinned badly can be justly blessed by joining itself to the Lord Jesus and receiving His sacrifice for sinful mankind. This little book is written to show this vital picture in the Bible, so that believers in Jesus will turn to Him and hear Him accurately.