Prior to the revision of the Breviary instituted by Pope St. Pius X, the Octave of St. Catherine of Siena would be celebrated today. This is one of the many octaves of the Dominican saints that were casualties of the revision of St. Pius X. Not all of the Dominican saints had octaves after their feast day, but the major ones like St. Catherine did. I think this is something that could have been retained, particularly as it was merely a commemoration at Lauds and Vespers. For the life of me, I do not see the harm in adding a commemoration, particularly of a saint that exemplifies so much of what the Order stands for.
In the 1909 Breviarium S.O.P., the octave was a solemn one, meaning that it ranked with other great octaves like that of St. Dominic and St. Thomas Aquinas. According to the Proper of the Saints, all was taken from the saints feast day, with the exception of Lessons i, ii, and iii at Matins, which were proper. These Lessons are extracts from the Bull of her Canonization. So today, we conclude our octave of St. Catherine of Siena.
O God, you enabled the blessed Catherine, graced with a special privilege of virginity and patience, to overcome the attacks of evil spirits and to remain unshaken in your love; grant, we beseech you, that following her example by treading underfoot the wickedness of the world, and overcoming the wiles of our enemies, we may pass tin safety to your glory. Through our Lord…