Winter Solstice became Christmas. Ostara was transformed into Easter. Finally Samhain became the modern secular feast of Halloween and the Christian feast of All Saint's Day.
Practice.
Druidism is a religion based on polytheism, and was made up of approximately 3 dozen Gods and Goddesses. Among these are, "Arawn, Brigid, Cernunnos, Ceridwen, Danu, Herne, Lugh, Morgan, Rhiannon, and Taranis. Each of the Gods is often represented in a threefold capacity, with the threefold Goddess being that of herself and her two sisters. .
The Druid community contained three main roles that of the Bard, the Ovate and the Druid. .
"The Bards were "the keepers of tradition, of the memory of the tribe - they were the custodians of the sacredness on the Word." In Ireland, they trained for 12 years learning grammar, hundreds of stories, poems, philosophy, and the Olgam tree alphabet.
The Ovates worked with the processes of death and regeneration. They were the native healers of the Celts. They specialized in divination, conversing with the ancestors, and prophesizing the future. .
The Druids and Druidesses formed the professional class in Celtic society. They performed the functions of modern day priests, teachers, ambassadors, astronomers, genealogists, philosophers, musicians, theologians, scientists, poets and judges. They underwent lengthy training: some sources say 20 years. Druids led all public rituals, which were normally held within fenced groves of sacred trees." (religioustolerance).
Druidism has an eight-part year divided by the eight major feasts of the year. The first of the four fire festivals, which start at sunset and last for three days is Samhain, which literally means the end of the warm season. This feast held on November 1 is both the Feast of the Dead and New Years day combined together. This is because according to Druid beliefs life both begins and ends and death and birth.