In Western Christianity, All Souls' Day commemorates the faithful departed. This day is observed in the Roman Catholic Church, churches of the Anglican Communion, Old Catholic Churches, and to some extent among Protestants. The Eastern Orthodox Church observes several All Souls' Days during the year. The Roman Catholic celebration is based on the doctrine that the souls of the faithful which at death have not been cleansed from venial sins, or have not fully atoned for mortal sins, cannot attain the beatific vision in heaven yet, and that they may be helped to do so by prayer and by the sacrifice of the Mass (see Purgatory).
All Souls' Day is also known as the Feast of All Souls, Commemoration of all the Faithful Departed. The official Latin designation Commemoratio omnium Fidelium Defunctorum, on which this last name is based, is rendered more literally in Portuguese Comemoração de todos os Fiéis Defuntos and many other languages. Day of the Dead (Día de los Muertos or de los Difuntos) is used in Spanish-speaking countries, and Thursday of the Dead (Yom el Maouta) in Lebanon, Palestine and Syria.
The Western celebration of All Souls' Day is on 2 November and follows All Saints' Day, which commemorates the departed who have attained the beatific vision. If 2 November falls on a Sunday, the Mass is of All Souls, but the Office is that of the Sunday. However, Morning and Evening Prayer (Lauds and Vespers) for the Dead, in which the people participate, may be said. In pre-1969 calendars, which some still follow, All Souls Day is instead transferred, whenever 2 November falls on a Sunday, to the next day, 3 November.
The Eastern Orthodox Church dedicates several days throughout the year to the dead, mostly on Saturdays, because of Jesus' resting in the tomb on Saturday.
A legend became associated with the institution of the celebration. According to Jesse Voyles in his Life of St Odilo, a pilgrim returning from the Holy Land was cast by a storm on a desolate island. A hermit living there told him that amid the rocks was a chasm communicating with purgatory, from which perpetually rose the groans of tortured souls. The hermit also claimed he had heard the demons complaining of the efficacy of the prayers of the faithful, and especially the monks of Cluny, in rescuing their victims. Upon returning home, the pilgrim hastened to inform the abbot of Cluny, who then set 2 November as a day of intercession on the part of his community for all the souls in purgatory.
(In the Serbian Orthodox Church there is also a commemoration of the dead on the Saturday closest to the Conception of St. John the Baptist—September 23)
Saturdays throughout the year are devoted to general prayer for the departed, unless some greater feast or saint's commemoration occurs.
Among continental Protestants its tradition has been more tenaciously maintained. Even Luther's influence was not sufficient to abolish its celebration in Saxony during his lifetime; and, though its Ecclesiastical sanction soon lapsed even in the Lutheran Church, its memory survives strongly in popular custom. Just as it is the custom of French people, of all ranks and creeds, to decorate the graves of their dead on the jour des morts, so German people stream to the graveyards once a year with offerings of flowers.
In Bolivia, many people believe that the dead eat the food that is left out for them. Some claim that the food is gone or partially consumed in the morning.