Today is when Christians, without saying so, celebrate the absorption of a pagan goddess and festival. (Neither of these, directly, has aught to do with Groundhog’s Day.)
For Christians, this is the day for celebrating the Purification–the rites that Mary followed by bringing Jesus to the Temple and offering two pigeons as a sin offering–done despite (as Butler explains ad nauseam) the lack of need on either Mary’s or the infant Jesus’s part to atone for anything.
Butler then goes on to explain that this day is also for the celebration of Candlemas–a procession with lighted candles that Christian tradition says began at that time of Purification, when Mary and Joseph, Simeon and Anne, two-by-two, marched forth (presumably from the Temple) to proclaim Christ as the “true light” and to offer a “light for the enlightening of the Gentiles.”
Christians placed this holiday over top the pagan festival known by different names, though among the Celts it was called Imbolc. Imbolc was a celebration of the Brigid (goddess of fertility), complete with candles, bonfires, and feasting (celebrating the lengthening of days, here at the mid-point between solstice and equinox). Christianity went further, and even appropriated the Celtic goddess Brigid, transforming her into a Saint (celebrated yesterday, the start of Imbolc!) and made her an abbess of an ancient Irish nunnery.
In Mary, Christians made the Virgin into the Fertile One; with Brigid, they made the Fertile One into a Virgin.
The traditions of the Triple Goddess honor Her as Maiden, Mother, and Crone, recognizing that the Goddess can be as She chooses, and that Hers is not a linear existence. Nor, like Mary, is the Goddess forever frozen as always and only the Virgin.
Alas, Candlemas–meant to celebrate illumination–represents an extinguishing of So Much More.