Pope St. Gregory I, also known as “the Great”, made it very clear that we are not to say Jesus Christ did not know when the end of the world would come. In the Pope’s Epistle, “Sicut agua frigida”, he writes: “ It is written: In the Beginning was the Word, and the Word was with God, and the Word was God…All things were made by him (John 1:13 ). If all, then without doubt also the day of Judgment and the hour. Who, therefore, is so foolish as to presume to assert that the Word of the Father made that which He does not know? It is writ ten also: Jesus knowing that the Father gave him all things into his hands (John 13:3). If all things, surely both the day of judgement and the hour. Who, therefore, is so stupid as to say that the Son has received in His hands that of which He is unaware?”
However, because of the abuses of the clergy who were causing hysteria and anxieties in trying to get sinners to repent by date setting the End of the World for their times [“False prophets shall rise and seduce many” (Matt. 24:11)], Pope Leo X, at the Fifth Lateran Council, made it mandatory that henceforth permission had to be obtained from either the local Ordinary or the Apostolic See before one could set the exact date for the End of the World.
The confusion in regards to the End Times is in distinguishing the difference in date setting and naming the day of the week on which Our Lord will come back.
To illustrate—in the coming chastisement—the day that the fire comes down from the Heavens would be referred to as the Day of the Lord, as He inflicts His punishment upon the enemies of the Church. The Day of the Lord can be any day of the week He chooses. If, on the other hand, it were to have been revealed that this event would take place on the Lord’s Day, then we could safely indicate that this event would take place starting on a Sunday. So it goes with the Coming of the Lord, as all obvious signs, revelation, and tradition tell us that Jesus Christ will come back on Sunday (cf. Apoc.1: 10). This is what motivated me to put together my two booklets, “The Day of the Lord” and “The Great Apostasy”. These books cover the subject in more depth.
Again, by picking Sunday as the day, one is not date setting. Hence, one does not need to seek permission. However I do have a Nihil Obstat on my “Day of the Lord.” booklet by more than one Bishop.
Pointing out which Sunday does not date set either, as the liturgical calendar changes from year to year.
The Church prepares us for our Salvation on a daily basis and also prepares us for the general judgment by making Sunday a Holy Day of Obligation and making it mandatory that one receives Holy Communion during the Easter Season.
If then thou shalt not watch I will come to thee as a thief and thou shalt not know at what hour I will come to thee (Apoc. 3:3).
If anyone says that Jesus Christ WILL NOT COME BACK ON PENTECOST SUNDAY, he just simply does not know his Catholic faith as well as he should.
Grace be with you through Mary our Hope, In Christ, Joseph
Catechism of the Council of Trent , TAN Books and Publishers, Rockford , IL
Catechism Explained, The, by Rev. Francis Spirago, TAN Books and Publishers, Rockford, IL, 1921 ed. reprinted 1993
Decrees of the Ecumenical Councils, Norman P. Tanner, Sheed & Ward, Georgetown
Douay-Rheims Bible, Tan Books and Publishers, Rockford , IL ,
Manual of Dogmatic Theology, by A. D. Tanquerey, Desclee , New York , 1959
Sources of Catholic Dogma , The, by Roy J. Defferari, B. Herder, St. Louis , 1957 [Denzinger]
Saint Andrew Bible Missal, DDB Publishers, 1962