Imbolc (pronounced Im'olk) is a pagan holiday celebrated from February 1st through to sundown on February 2nd.
Based on a Celtic tradition, Imbolc was meant to mark the halfway point between winter solstice and the spring equinox in Neolithic Ireland and Scotland.
The earliest mentions of Imbolc in Irish literature date back to the 10th century. Poetry from that time relates the holiday to ewe’s milk, with the implication of purification.
In pre-Christian times, Imbolc observance began the night before February 1st. Celebrants prepared for a visit from the Goddess Brigid into their homes by crafting an effigy of her from bundles of oats and rushes. The effigy was placed in a dress and put in a basket overnight.
The day of Imbolc was celebrated by burning lamps and lighting bonfires in tribute to Brigid.
Candlemas is a Christian holiday celebrated on February 2nd that has aspects in common with Imbolc. Its celebration can be traced to 4th century Greece as a purification holiday and a celebration of the return of light.
Candles have traditionally been used in its observance. It’s possible that Candlemas is a Christian adaptation of the Roman holiday Februalia.
Or even Groundhog Day...
February 2nd is also celebrated as Groundhog Day, which began in the United States in 1887. The idea is that a groundhog exiting its burrow can predict whether winter will stay or go based on whether the groundhog sees its shadow. The day was a stunt by a newspaper in Punxsutawney, Pennsylvania, that has endured.
Thanks to www.history.com for the details.