The annual celebration is the last day of Allhallowtide, after All Saints' Day and its eve. Prior to the standardization of Catholic observance on 2 November by St. Odlio of Cluny during the 10th century, many Catholic congregations celebrated All Souls Day on various dates during the Easter season as it is still observed in some Eastern Orthodox Churches and associated Eastern Catholic Churches. Churches of the East Syriac Rite (Syro-Malabar Catholic Church, Chaldean Catholic Church, Assyrian Church of the East, Ancient Church of the East) commemorate all the faithful departed on the Friday before Lent.