ABSTRACT
On the example of the transition of Irenaeus’s feast days, this chapter explains the complex mechanisms that worked towards remembering and forgetting saints in calendars and hagiographical collections arranged by calendars. Irenaeus was gradually neglected and eventually lost his feast day in the period formative for calendars in the East and the West. His initial feast day changed dates several times until other saints replaced him; at times, he did not get into certain prominent hagiographical collections. The gradual neglect and disappearance of Irenaeus from such collections led to diminished remembering and, eventually, forgetting of the saint. It prevented him from contributing to mnemonic synchronization, which maintained collective memory among the discussed groups and societies.
