There are certain events in history that most people would remember. Even if it didn't affect them directly, they would be able to recall exactly where they were and what they were doing when it occurred. For many Americans in the United States, it would be events like the assassination of the country's President John F. Kennedy on 22 November 1963, the resignation of President Richard Nixon on 9 August 1974, and the attack on the World Trade Center in New York on 11 September 2001. These are days that live in infamy in Americans' collective and individual memory.

There are also days that we anticipate with overwhelming excitement–like the first day of a new job, our wedding day, moving into one's first home, the birth of a child, or a long-awaited retirement.

There is a day in Scripture that is like that too, a day which everyone looks towards, some with great anticipation and others with great trepidation. It is the ″day of the Lord″, often referred to as ″that day″ (Amos 8:9). Amos mentions it many times (see, for example, 2:16; 5:18, 20; 8:3, 13), and each mention is in reference to a day of punishment, sadness, sorrow, destruction, and death.

Amos isn't the only prophet to mention this day. Isaiah, Ezekiel, Joel, Obadiah, Zephaniah, Zechariah, and Malachi all refer to it in the Old Testament. It is also mentioned in Acts, 1 and 2 Corinthians, 1 and 2 Thessalonians, and 2 Peter in the New Testament. It is also likely alluded to in Revelation.

The ″day of the Lord″ refers to a time when God intervenes directly in human history to accomplish some part of His overarching goal, for both good and punishment. Many of the references can be understood to point to an event (or series of events) that will take place at the end of human history, just before the consummation of God's kingdom. But there are also interim ″days of the Lord″ when God sends discipline on His people to call them back to covenant faithfulness.

The ″day of the Lord″ is a day to be feared. It is a day of darkness and mourning. It will be a day of great loss, like the loss of an only son (v. 10). It is a day that will be remembered by those who experience it. No one will miss it or forget it when God visits His people.