Nativity of the Blessed Virgin Mary, 8 September

The Nativity of the Blessed Virgin Mary falls on the eighth of September, the date this rule records, set exactly nine months after the Feast of the Immaculate Conception on the eighth of December, the same forward counting logic the calendar applies to place Christmas nine months after the Annunciation. The feast's origin is traced to the dedication of a church in Jerusalem, generally identified with the traditional site of Mary's family home near the Pool of Bethesda, later remembered as the Basilica of Saint Anne, an event placed around the fifth or sixth century from which the September date is thought to derive.

The feast is kept, on the identical date, by new-calendar Orthodox churches sharing the Gregorian eighth of September with the West, while old-calendar Orthodox churches, including the Russian, Serbian and Georgian Orthodox churches, the Patriarchate of Jerusalem and the Mount Athos monasteries, observe fixed feasts by the Julian calendar, so their eighth of September falls on the twenty first of September Gregorian, the same thirteen day drift that separates their Christmas from the twenty fifth of December. Its relatively simple theological content, marking a birth rather than carrying the doctrinal weight of feasts like the Immaculate Conception or the Assumption, may be part of why it produced no comparable controversy or later dogmatic definition, remaining instead one of the calendar's more quietly stable Marian dates even as debate continued around the more theologically loaded feasts placed nine months before and after it.