As I mention from time, one of the brothers here set up a 1954 Missale Romano-Seraphicum in one of our hallways as a museum piece. Partly for my own amusement and edification, and partly out of rebellion, I set it up as if for Mass each day whenever I go by. It is an interesting practice, because there are many observances that do not appear in the 1962 Seraphic missal or breviary. It's like a little trip into the 'extra-extraordinary form.'
Today I notice that tomorrow is one such Franciscan feast that I had never heard of:
"The solemn commemoration of our holy father Francis, confessor." What gives? An extra feast of St. Francis apart from the celebration of his birth into eternal life in October?
A little Googling reveals that this is supposed to be the feast of the "profession of St. Francis," but to what event in his life does it refer?
A look at the classic chronology of the life of St. Francis compiled by Omer Englebert and Raphael Brown (one of the real treasures of the older, Franciscan Omnibus of Sources edited by Marion Habig*) suggests that it was on April 16, 1208 that Bernard of Quintavalle and Peter Catanii joined Francis and became his first brothers.
Anonymous of Perugia 2:11 takes up the story this way. The three brothers had a priest open the gospels for them. Upon hearing the passages, If you wish to be perfect, Whoever wishes to come after me, and Take nothing for the journey, they exclaimed, "This is what we we want, this is what we were seeking." Francis goes on to say, "This will be our Rule." So I guess that amounts to a profession, and hence the feast day.
*If you want one, good luck. Try the bookstore at St. Francis of Assisi on 31st St. in Manhattan, where I recently noticed copies of the 1991, 2-volume reprint.