All Saints' Day

All Saints' Day is a solemn Holy day of the Catholic Church dedicated to the Saints of the Church, both those known and those unknown. It is celebrated on November 1st by the Roman Catholic Church, Anglican Communion, Methodist church, Lutheran church, and many other protestant groups; the Eastern Orthodox, Eastern Catholic and Byzantine Lutheran churches celebrate on the first Sunday after Pentecost. It is a day that celebrates all who have attained the beatific vision in Heaven.
In the Western Catholic practice, the liturgical celebrations begin the evening before, the 31st of October (All Hallows' Eve). On All Hallows' Eve, the celebration starts at Vespers and All Saints' Day is often time part of the three days called Allhallowtide (All Hallows' Eve, All Saints' Day, and All Souls' Day). Hallow, in Old English means Holy or Sacred.
According to Saint Ephraem Syrus, a feast of all martyrs was held and celebrated on May 13th of every year in the Eastern Church - it is possible that this influenced Pope Boniface IV's later decision of what day to hold the future Holy Day. Saint Maximus of Turin preached sermons in honor of all Christian Martyrs annually on the Sunday after Pentecost in Northern Italy beginning in the 5th century, and the Comes of Wurzburg lists the Sunday after Pentecost as "dominica in natale sanctorum" (Sunday of the Nativity of the Saints".
On May 13th, 609 Pope Boniface IV consecrated the Pantheon in Rome as a Church to the Blessed Virgin and all martyrs. Though likely chosen as the date due to the preexistence of a feast for Martyrs (see above) in the Eastern Church on May 13th, it may also have co-opted the pagan holiday "Feast of the Laures", a feast pagans placated the restless spirits of the dead. Pope Boniface IV also established "All Souls' Day".
In 731, Pope Gregory III dedicated an oratory in Saint Peter's Basilica for the relics of
"of the holy apostles and of all saints, martyrs and confessors, of all the just made perfect who are at rest throughout the world"
He also established the feast of All Saints formally, moving the date from May 13th to October 27th (November 1st O.S.) The Archbishop Arno of Salzburg called for the festival to be held in Southeast Germany to great success and acclaim, and in 835 Louis the Pious, at the instance of Pope Gregory IV and the assent of all the Bishops, established All Saints' Day as a day of obligation in the Frankish Empire.
In the Medieval England, the festival became known as All Hallows, which gave away on the night before to Halloween (Hallows' Eve).
Customs around the world
France
In France, the day is known as La Toussaint. Chrysanthemums and wreaths called 'couronnes de toussaints' are placed at tombs and graves
Belgium
In Belgium the holiday is known as Toussaint or Allerheiligen and is a public holiday. Pople typically follow the French custom of placing Chrysanthemums on graves.
Portugal
Known as Dia de Todos os Santos, the day is a national holiday with visits to cemetaries. Children travel door to door receiving cakes, candies and fruits.
Austria
In Asustria and much of Bavaria, Godfathers give their Godchildren braided yeast pastries called Allerheiligenstriezel.
Mexico
All Saints' Day in Mexico is the first day of the Dia de Muertos celebration and commemorates Children who have died (Dia de los Inocentes)
Guatemala
In Guatemala, the day is a national holiday and Guatemalans make a special meal called fiambre. They take some of this meal to the cemeteries of their loved ones and leave portions for them; some fly massive colorful kites to help unite the living with the dead.
Philippines
In the Philippines the day is called Undas, Todos Los Santos, and Araw ng mga Patay / Yumao (in Tagalog - Day of the Dead/ Those who have passed). Many take the day cleaning up family tombs and leave offerings of prayers, flowers and candles. The American Halloween traditions are fully celebrated here as well, with trick or treating.
Litany of the Saints
We invite you to join in the Litany of the Saints at EWTN.com -
https://www.ewtn.com/catholicism/devotions/litany-of-the-saints-250