Samhain

Samhain is one of the eight annual holidays, 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 most Wiccans as a celebration of death and of the dead, 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 and death, which is balanced at the opposite point of the wheel by the spring festival of Beltane, which Wiccans celebrate as a festival of life and fertility.
While the Wiccan version of Samhain is not a form of reconstruction, and is largely mixed with other traditions in a form of universalism, it is influenced by the Celtic holiday from which the name was taken.