Avodah Zarah 8 - The Origin of Calenda and Saturnalia
The pagan festivals that are subject to the three-day business restrictions are Calenda, Saturnalia, and Kratesis. The festival of Calenda is celebrated for eight consecutive days following the winter solstice, which is the shortest day of the year, whereas Saturnalia is celebrated for eight days preceding the winter solstice. The mnemonic to remember that the first festival is mentioned last is " Later and earlier You formed me ..."
When Adam the first man saw the days decreasing in winter, he said, "Woe is to me! This is the death that has been decreed upon me!" He then engaged in fasting and prayer for eight days. When after winter solstice he saw that the days began increasing, he said, "This is the way of the world!" and established eight days of festivities. The following year he established both eight-day periods as festival days. Although he intended for the sake of Heaven, later generations dedicated them for the sake of idolatry.
Art: Frederick Cayley Robinson - A Winter Evening