Friday of the Thirteenth Week of Ordinary Time

On that day, says the Lord God,
I will make the sun set at midday
and cover the earth with darkness in broad daylight.

The 9th century BC prophet Amos is the first to speak of a future day – “that day” – when God will set things right. He predicts it will be a dreadful day, the kind of day parents used to threaten their children: “One of these days, Buster – POW! – right in the chops.”

In Catholic parlance, it will be a dies irae, dies illa – which you might remember from the pre-Vatican funeral liturgy:

Dies irae, dies illa solvet saeclum in favilla, teste David cum Sibylla.

Day of wrath, day that will dissolve the world into burning coals, as David bore witness with the Sibyl.

Incidentally, this song was written by the Thomas of Celano, the Franciscan who wrote the Legend of Saint Francis of Assisi in preparation for his canonization. The tune, of course, appears in countless familiar places, including Berlioz’s Symphonie Fantastique. It is appropriately ominous.

Thankfully, in his ninth chapter, verse four, Amos allows a few blessings to appear, “ On that day I will raise up the fallen hut of David; I will wall up its breaches, raise up its ruins, and rebuild it as in the days of old.”

The symbol of “that day” in Amos is important because it gradually turns the attention of God’s people – and our religion – toward the future. Though Amos is nostalgic for the past, which he considers better than the present, he knows the future will come. And it must bring a blessing with it, for those few who remain faithful.

Later prophets will use “that day” for both threat and promise. In our Catholic tradition it blossoms as the Day of Judgment, the end of the world, when the Lord the Just Judge will sort out the nations according to his true standards of justice and mercy. 

As to whether "that day" will be wonderful or dreadful -- you be the judge.

A lesser known Franciscan poet has written of that day: Judgment Day

The winds shall separate the chaff from wheat
as trumpets sound the coming of the Day.
The meek and poorest of the earth will stand to greet
The victor with his crown of thorns. They’ll say
“We shared our gifts with him, the few we had,
our anxious faith, and soiled love, our tremb-
ing hope, the stored up wealth of sad
long years. We brought them all to Bethlehem –
and Calvary. Who could expect this grace
appearing to us now? The wealthy too
will hail his justice as his broken mace
adjudicates atoning peace. Renewed
in all her cycling seasons Earth shall kiss
in ecstasy the consort of her bliss.