It is often recounted that Imbolc (or Óimelc) was the ancient pagan origin of St Brigid's day (the 1st of February) marking the start of Spring. It is commonly said that Imbolc was a fertility festival with various rituals and it was christianised into the Christian tradition of St Brigid's day. Many go as far as to say that the saint didn't exist at all and another link here. This seemed logical as a figure called Brigid appears in Irish mythology. Some articles about the Goddess mention a sacred fire in Kildare that was kept burning by virgins.
It was said to be one of the four great Celtic festival, quarter days that divided the year. It sounds very convincing but I have been trying to learn more.
The only direct evidence that I can find for the existence of Imbolc is a single reference in Sanas Cormaic/ Cormac's Glossary, which simply mentions Óimelc and simply defines it as the beginning of spring and the word comes the word for ewe's milk. This is 10th cen so it is about 500 years after Patrick. I can't find a single other example of hard evidence of Imbolc. The ancient goddess figure of Brighid isn't associated with Imbolc in cormac's glossary. Increasingly it seems that the much discussed traditions seem to be have been inferred from folk traditions of St Brigid which creates a circular logic issue. Does anyone have thoughts?