After Imbolc on Feb. 1st, Candlemas falls on Feb. 2nd. While both are seen as origins of Groundhog Day, Imbolc is a Pagan festival, while Candlemas is a Christian festival. In the 6th century the Christian Church, as it did with many other pagan gods and goddesses, declared the goddess Brigid to be St. Brigid, and established Feb. 1st as her annual festival.
Remember that the only Christian Church at this time was the Roman Catholic Church until Henry VIII abolished it in England in 1534. The Roman Catholic Church has always been very active in naming Saints, even today.
St. Brigid, native to Ireland, was the 'Grain Goddess', representing fertility during the coming year. She established several nunneries, including the famous one at Kildare. And she was one of the three patron Saints of Ireland, a contemporary of St. Patrick and St. Columba.
You therefore have a choice of celebrating Groundhog Day either as a Pagan or a Christian, but either one is a focus on spring, and the growing season to come. You also have the choice of either Feb. 1st or 2nd; the literature isn't very clear on that.
It certainly would have a much later date here in southern Ontario to avoid the snow!