St. Francis instituted the celebration of a Mass each Saturday in honor of the Immaculate Conception

Source: Google Books

In this Chapter [of 1292], what Saint Bonaventure had already ordained was renewed, namely that each Provincial should bring to the general assemblies an account of everything noteworthy that had occurred in his Province.

It was ordered that the proper Hymns of Saint Clare should be said. What Saint Francis had instituted and what Saint Bonaventure had confirmed was renewed: that every Saturday, or on another day of the week, a Mass should be sung in honor of the Immaculate Conception of the Blessed Virgin…"