Beltane: (Bealtaine, May Eve, Valpurgis) - April 30th/May 1st
The Fire Festival of Beltane
This festival is also known as Beltane, the Celtic May Day. It officially begins at moonrise on May Day Eve, and marks the beginning of the third quarter or second half of the ancient Celtic year. It is celebrated as an early pastoral festival accompanying the first turning of the herds out to wild pasture. The rituals were held to promote fertility. The cattle were driven between the Belfires to protect them from ills. Contact with the fire was interpreted as symbolic contact with the sun. In early Celtic times, the druids kindled the Beltane fires with specific incantations. Later the Christian church took over the Beltane observances, a service was held in the church, followed by a procession to the fields or hills, where the priest kindled the fire. The rowan branch is hung over the house fire on May Day to preserve the fire itself from bewitchment (the house fire being symbolic of the luck of the house).
http://www.thewhitegoddess.co.uk/the_wheel_of_the_year/beltane.asp