Easter Monday & Easter Tuesday as Holy Days of Obligation

When writing about the rank of days in the Catholic Liturgical calendar, there are various ways to label them. In the modern Church, they will use the terms solemnity, feast, memorial, or optional memorial. In the 1962 Missal, we have First, Second, Third, or Fourth Class feastdays. But before the 1962 Missal up until the changes made by Pope Pius XII in 1955, there were from least to most important: Simples, Semidoubles, Lesser Doubles or also known as Doubles, Greater Doubles, Doubles of the second class, and lastly Doubles of the first class.   Using the traditional pre-1955 calendar, we notice something very interesting about Easter Monday and Easter Tuesday. Easter Monday and Tuesday are doubles of the first class whereas the rest of the Easter Octave is a semi-double.  Even with the variation in rank, the Easter Octave is privileged and no other feastday may occur in the Octave.    But what's unique about Easter Monday and Easter Tuesday is that no other saints are commemorated those days in the Mass or the Divine Office.
Why the special treatment for Easter Monday and Easter Tuesday? It is because they were universal holy days of obligation for a very long time. Easter Tuesday was not dropped from the list until 1771 by Pope Clement XIV; Easter Monday was dropped from the universal list at the beginning of the 20th century but is still a Holy Day of Obligation in many places to this very day. In Catholic European countries, it is still common to have Easter Monday off as a paid holiday.

The unequaled Dom Gueranger, in his seminal work, The Liturgical Year, writes:

So fervently did the faithful of those times appreciate and love the Liturgy, so lively was the interest they took in the newly made children of holy mother Church, that they joyfully went through the whole of the services of this week. Their hearts were filled with the joy of the Resurrection, and they thought it but right to devote their whole time to its celebration. Councils laid down canons, changing the pious custom into a formal law. The Council of Mâcon, in 585, thus words its decree: ‘It behoves us all fervently to celebrate the feast of the Pasch, in which our great High Priest was slain for our sins, and to honour it by carefully observing all it pre-scribes. Let no one, therefore, do any servile work during these six days (which followed the Sunday), but let all come together to sing the Easter hymns, and assist at the daily Sacrifice, and praise our Creator and Redeemer in the evening, morning, and mid-day.’ 

The Councils of Mayence (813) and Meaux (845) lay down similar rules. We find the same prescribed in Spain, in the seventh century, by the edicts of kings Receswind and Wamba. The Greek Church renewed them in her Council in Trullo; Charlemagne, Louis the Good, Charles the Bald, sanctioned them in their Capitularia; and the canonists of the eleventh and twelfth centuries, Burchard, St Ivo of Chartres, Gratian, tell us they were in force in their time. Finally, Pope Gregory IX inserted them in one of his decretals in the thirteenth century. But their observance had then fallen into desuetude, at least in many places. The Council held at Constance, in 1094, reduced the solemnity of Easter to the Monday and Tuesday. 

The two great liturgists, John Beleth in the twelfth, and Durandus in the thirteenth century, inform us that, in their times, this was the practice in France. It gradually became the discipline of the whole of the western Church, and continued to be so, until relaxation crept still further on, and a dispensation was obtained by some countries, first for the Tuesday, and finally for the Monday. In order fully to understand the Liturgy of the whole Easter Octave (Low Sunday included), we must remember that the neophytes were formerly present, vested in their white garments, at the Mass and Divine Office of each day. Allusions to their Baptism are continually being made in the chants and Lessons of the entire week.