The Constitutions of Ratisbona, approved in 1290, already mandated and stated in Chapter VI that «the anniversary of our deceased fathers, mothers, familiars and benefactors, shall be celebrated every year in all the houses of our Order on the first ferial day after the feast of Saint Agueda [February 6].
And in order that these anniversaries are not be forgotten, let them be written in the calendar and at the proper time let them be read in the chapter in the manner of feasts» (Chap. VI, n. 44).
The commemoration, which was transferred to the 19th of February in the reformation made by Pius X in the year 1914, was moved and fixed on January 16 in the reformation of 1975.