The Winter Solstice is the shortest day and night of the year. It typically occurs between December 21 and 23. Cultures around the world recognize the Winter Solstice in different ways. In the past, it was used as a way of monitoring the reserves of food, as winter could be long and harsh. Sol Invictus, the sun god of Syrian culture, is celebrated on December 25 in relation to the Winter Solstice.