The Divalia (December 21) was the fifth day of the Saturnalia and marked the winter solstice. It was a festival in honor of Angerona, the goddess of secrecy believed to give relief from pain and worry. She was usually depicted with a finger placed on her sealed mouth, warning silence, since she bore the secret and potent name of Rome. A sacrifice was offered to her image at the Palatine altar of Volupia.
On Old English calendars, the day was known as Geol, from which we get the word "yule."