The Gaulish calendar appears to have divided the year into two halves: the 'dark' half, beginning with the month Samonios (the October/November lunation), and the 'light' half, beginning with the month Giamonios (the April/May lunation). The entire year may have been considered as beginning with the 'dark' half, so that the beginning of Samonios may be considered the Celtic New Year's day. The celebration of New Year itself may have taken place during the 'three nights of Samonios' (Gaulish trinux[tion] samo[nii]), the beginning of the lunar cycle which fell nearest to the midpoint between the autumnal equinox and the winter solstice. The lunations marking the middle of each half-year may also have been marked by specific festivals. The Coligny calendar marks the mid-summer moon (see Lughnasadh), but omits the mid-winter one (see Imbolc). The seasons are not oriented at the solar year, viz. solstice and equinox, so the mid-summer festival would fall considerably later than summer solstice, around 1 August (Lughnasadh). It appears that the calendar was designed to align the lunations with the agricultural cycle of vegetation, and that the exact astronomical position of the Sun at that time was considered less important.
In medieval Ireland, Samhain became the principal festival, celebrated with a great assembly at the royal court in Tara, lasting for three days. After being ritually started on the Hill of Tlachtga, a bonfire was set alight on the Hill of Tara, which served as a beacon, signaling to people gathered atop hills all across Ireland to light their ritual bonfires.. The custom has survived to some extent, and recent years have seen a resurgence in participation in the festival.
Samhain came to be described as "Celtic New Year" in 18th century literature From this usage in the Romanticist Celtic Revival, Samhain is still popularly regarded as the "Celtic New Year" in the contemporary Celtic cultures, both in the Six Celtic Nations and the diaspora. For instance, the contemporary calendars produced by the Celtic League begin and end at Samhain.
The Samhain celebrations have survived in several guises as a festival dedicated to the harvest and the dead. In Ireland and Scotland, the Féile na Marbh, the 'festival of the dead' took place on Samhain.
The night of Samhain, in Irish, Oíche Shamhna and Scots Gaelic, Oidhche Shamhna, is one of the principal festivals of the Celtic calendar, and falls on the 31st of October. It represents the final harvest. In modern Ireland and Scotland, the name by which Halloween is known in the Gaelic language is still Oíche/Oidhche Shamhna. It is still the custom in some areas to set a place for the dead at the Samhain feast, and to tell tales of the ancestors on that night.
Traditionally, Samhain was time to take stock of the herds and grain supplies, and decide which animals would need to be slaughtered in order for the people and livestock to survive the winter. This custom is still observed by many who farm and raise livestock.
Bonfires played a large part in the festivities celebrated down through the last several centuries, and up through the present day in some rural areas of the Celtic nations and the diaspora. Villagers were said to have cast the bones of the slaughtered cattle upon the flames. In the pre-Christian Gaelic world, cattle were the primary unit of currency and the center of agricultural and pastoral life. Samhain was the traditional time for slaughter, for preparing stores of meat and grain to last through the coming winter. The word 'bonfire', or 'bonefire' is a direct translation of the Gaelic tine cnámh. With the bonfire ablaze, the villagers extinguished all other fires. Each family then solemnly lit its hearth from the common flame, thus bonding the families of the village together. Often two bonfires would be built side by side, and the people would walk between the fires as a ritual of purification. Sometimes the cattle and other livestock would be driven between the fires, as well.
Divination is a common folkloric practice that has also survived in rural areas. The most common uses were to determine the identity of one's future spouse, the location of one's future home, and how many children a person might have. Seasonal foods such as apples and nuts were often employed in these rituals. Apples were peeled, the peel tossed over the shoulder, and its shape examined to see if it formed the first letter of the future spouse's name. Nuts were roasted on the hearth and their movements interpreted - if the nuts stayed together, so would the couple. Egg whites were dropped in a glass of water, and the shapes foretold the number of future children. Children would also chase crows and divine some of these things from how many birds appeared or the direction the birds flew.
The Ulster Cycle is peppered with references to Samhain. Many of the adventures and campaigns undertaken by the characters therein begin at the Samhain Night feast. One such tale is Echtra Nerai ('The Adventure of Nera') concerning one Nera from Connacht who undergoes a test of bravery put forth by King Ailill. The prize is the king's own gold-hilted sword. The terms hold that a man must leave the warmth and safety of the hall and pass through the night to a gallows where two prisoners had been hanged the day before, tie a twig around one man's ankle, and return. Others had been thwarted by the demons and spirits that harassed them as they attempted the task, quickly coming back to Ailill's hall in shame. Nera goes on to complete the task and eventually infiltrates the sídhe where he remains trapped until next Samhain. Taking etymology into consideration, it is interesting to note that the word for summer expressed in the Echtra Nerai is samraid.
The other cycles feature Samhain as well. The Cath Maige Tuireadh (Battle of Mag Tuired) takes place on Samhain. The deities Morrígan and Dagda meet and have sex before the battle against the Fomorians; in this way the Morrígan acts as a sovereignty figure and gives the victory to The Dagda's people, the Tuatha Dé Danann.
The tale The Boyhood Deeds of Fionn includes an important scene at Samhain. The young Fionn Mac Cumhail visits Tara where Aillen the Burner, one of the Tuatha Dé Danann, puts everyone to sleep at Samhain and burns the place. Through his ingenuity Fionn is able to stay awake and slays Aillen, and is given his rightful place as head of the fianna.
In parts of western Brittany, Samhain is still heralded by the baking of kornigou, cakes baked in the shape of antlers to commemorate the god of winter shedding his 'cuckold' horns as he returns to his kingdom in the Otherworld. The Romans identified Samhain with their own feast of the dead, the Lemuria. This, however, was observed in the days leading up to May 13. With Christianization, the festival in November (not the Roman festival in May) became All Hallows' Day on November 1 followed by All Souls' Day, on November 2. Over time, the night of October 31 came to be called All Hallow's Eve, and the remnants festival dedicated to the dead eventually morphed into the secular holiday known as Halloween.
The Welsh equivalent of this holiday is called Nos Galan Gaeaf. As with Samhain, this marks the beginning of the dark half of the year and it officially begins at sundown on the 31st.
Isle of Man
The Manx celebrate Hop-tu-Naa, which is a celebration of the original New Year's Eve. The term is Manx Gaelic in origin, deriving from Shogh ta’n Oie, meaning "this is the night". Traditionally, children dress as scary beings, carry turnips rather than pumpkins and sing an Anglicized version of Jinnie the Witch. They go from house to house asking for sweets or money,
Samhain is observed by various Neopagans in various ways. As forms of Neopaganism can differ widely in both their origins and practices, these representations can vary considerably despite the shared name. Some Neopagans have elaborate rituals to honor the dead, and the deities who are associated with the dead in their particular culture or tradition. Some celebrate in a manner as close as possible to how the Ancient Celts and Living Celtic cultures have maintained the traditions, while others observe the holiday with rituals culled from numerous other unrelated sources, Celtic culture being only one of the sources used.
Celtic Reconstructionist Pagans tend to celebrate Samhain on the date of first frost, or when the last of the harvest is in and the ground is dry enough to have a bonfire. Like other Reconstructionist traditions, Celtic Reconstructionists place emphasis on historical accuracy, and base their celebrations and rituals on traditional lore from the living Celtic cultures, as well as research into the older beliefs of the polytheistic Celts. At bonfire rituals, some observe the old tradition of building two bonfires, which celebrants and livestock then walk or dance between as a ritual of purification.
According to Celtic lore, Samhain is a time when the boundaries between the world of the living and the world of the dead become thinner, at times even fading away completely, allowing spirits and other supernatural entities to pass between the worlds to socialize with humans. It is the time of the year when ancestors and other departed souls are especially honored. Though Celtic Reconstructionists make offerings to the spirits at all times of the year, Samhain in particular is a time when more elaborate offerings are made to specific ancestors. Often a meal will be prepared of favorite foods of the family's and community's beloved dead, a place set for them at the table, and traditional songs, poetry and dances performed to entertain them. A door or window may be opened to the west and the beloved dead specifically invited to attend. Many leave a candle or other light burning in a western window to guide the dead home. Divination for the coming year is often done, whether in all solemnity or as games for the children. The more mystically inclined may also see this as a time for deeply communing with the deities, especially those whom the lore mentions as being particularly connected with this festival.
- Main article: Wheel of the Year
Samhain is one of the eight annual festivals, often referred to as 'Sabbats', observed as part of the Wiccan Wheel of the Year. It is considered by most Wiccans to be the most important of the four 'greater Sabbats'. It is generally observed on October 31st in the Northern Hemisphere, starting at sundown. Samhain is considered by some Wiccans as a time to celebrate the lives of those who have passed on, and it often involves paying respect to ancestors, family members, elders of the faith, friends, pets and other loved ones who have died. In some rituals the spirits of the departed are invited to attend the festivities. It is seen as a festival of darkness, which is balanced at the opposite point of the wheel by the spring festival of Beltane, which Wiccans celebrate as a festival of light and fertility.