The General Roman Calendar of 1954 is the General Roman Calendar as it was in 1954.
The changes that the latter Pope made in 1955 are indicated in General Roman Calendar of Pope Pius XII.
Further information: Ranking of liturgical days in the Roman Rite
The ranking of feast days that had grown from an original division between doubles and simples.
In 1907, when, in accordance with the rules in force since the time of Pope Pius V, feast days of any form of double, if impeded by falling on the same day with a feast day of higher class, were transferred to another day, this classification of feast days was of great practical importance for deciding which feast day to celebrate on any particular day. Pope Pius X changed things in his 1911 reform of the Roman Breviary.
Before the reform of Pope Pius X in 1911, ordinary Doubles took precedence over most of the Semidouble Sundays, resulting in many of the Sunday Masses rarely being said. While retaining the Semidouble rite for Sundays, the reform permitted only the most important feast days, Doubles of the I or II class, to be celebrated on Sunday. When a feast of the rank of double of the I or II class fell on a Sunday, the Mass would be that of the feast, with a commemoration of the occurring Sunday; the Gospel of the omitted Sunday Mass would be read at the end of Mass instead of the usual Gospel "In principio erat Verbum" of St. John. When a feast of a rank lower than that occurred with a Sunday, the feast would be commemorated in the Sunday Mass by including a commemoration of the feast, and its Gospel would be read at the end of Mass, provided it was a "proper" Gospel, i.e. one not taken from the Common.
The Tridentine Calendar had many octaves, without any indication in the calendar itself of distinction of rank between them, apart from the fact that the Octave Day (the final day of the octave) was ranked higher than the days within the octave. Several octaves overlapped, so that, for instance, on 29 December the prayer of the saint of the day, Saint Thomas Becket, was followed by the prayers of Christmas, of Saint Stephen, of Saint John the Evangelist and of the Holy Innocents. The situation remained such until the reform of Pope Pius X.