Feast of Santa Lucia - December 11 in most Nordic countries

In the 1980s, my husband and I hosted an exchange student from Sweden, and he shared the custom of the Feast of Santa Lucia with us. Basically, it is light chasing away the dark.

From Wikipedia: St. Lucy/Lucia is one of few saints celebrated by the overwhelmingly Lutheran Scandinavian peoples (Danes, Swedes, Finns and Norwegians). The St. Lucy's Day celebrations retain many indigenous Germanic pagan, pre-Christian midwinter elements, and the practices associated with the day, predates the adoption of Christianity in Scandinavia, and is like much of Scandinavian folklore, and even religiosity today, based on the annual struggle between light and darkness.

The Nordic observation of St. Lucy is first attested in the Middle Ages, and continued after the Protestant Reformation in the 1520s and 1530s, although the modern celebration is only about 200 years old. It is likely that tradition owes its popularity in the Nordic countries to the extreme change in daylight hours between the seasons in this region.

The pre-Christian holiday of Yule, or jól, was the most important holiday in Scandinavia and Northern Europe. Originally the observance of the winter solstice, and the rebirth of the sun, it brought about many practices that remain in the Advent and Christmas celebrations today. The Yule season was a time for feasting, drinking, gift-giving, and gatherings, but also the season of awareness and fear of the forces of the dark.

Between Lussi Night (December 13 by the unreformed Julian Calendar and the longest night of the year) and Yule, trolls and evil spirits, in some accounts also the spirits of the dead, were thought to be active outside. It was particularly dangerous to be out during Lussi Night. Children who had done mischief had to take special care, since Lussi could come down through the chimney and take them away, and certain tasks of work in the preparation for Yule had to be finished, or else the Lussi would come to punish the household. Another company of spirits might come riding through the night around Yule itself, journeying through the air, over land and water. It is tempting to look at Father Christmas’ journey with his reindeer as a commercial relic inspired by this superstition.

St. Lucy: Although no sources of her life exist other than in hagiographies, St. Lucy is believed to have been a Sicilian saint who suffered a martyr's death in Syracuse, Sicily around AD 310. According to one story, Saint Lucy was working to help Christians hiding in the catacombs during the terror under the Roman Emperor Diocletian, and in order to bring with her as many supplies as possible, she needed to have both hands free. She solved this problem by attaching candles to a wreath on her head

There is little evidence that the legend itself derives from the folklore of northern Europe, but the similarities in the names ("Lussi" and "Lucia"), and the date of her festival, December 13, suggest that two separate traditions may have been brought together in the modern-day celebrations in Scandinavia.