Liberius chose the date "because the people of Rome already observed it as the Feast of Saturn, celebrating the birthday of the Sun" according to The World Book Encyclopedia.
Letsatsi leo le tlhophilwe ka gonne, jaaka The World Book Encyclopedia e bua, "batho ba kwa Roma ba ne ba ntse ba keteka letsatsi leo e le Moletlo wa Saturn, ba keteka botsalo jwa letsatsi."