All Saints' Day and All Souls' Day
The proximity to winter and the symbolism have over time led to All Saints' Day and All Souls' Day merging into a double religious festival.
All Saints' Day is a solemnity on which all saints are remembered, both those canonized by the Pope and those "whose holiness only God knows".
In 835 Pope Gregory IV set November 1 for the entire Western Church (in the Orthodox churches the feast is celebrated on the first Sunday after Pentecost).
All Souls' Day, one day later, is the day of remembrance for the deceased. Abbot Odilo of Cluny proclaimed 998 this day in addition to the commemoration day (at first only) for the deceased of the monasteries subordinated to him. With solemn processions, grave blessing, decoration with flowers and green branches and the setting up of the soul light the deceased relatives are commemorated.
In Latin America the intercession for the souls of the deceased in purgatory (Dia de los Muertos and Dia de los Difuntos) is a colourful and joyful celebration. Traditionally, families gather in the cemeteries to picnic and make music with the deceased.