Religious festivals are recurring, significant events observed by adherents of a faith, with their study known as heortology. In Ancient Rome, feriae were a cornerstone of religious life, divided into public, state-funded celebrations and private observances. These "holy days," defined by the 1st-century BC scholar Varro as "days instituted for the sake of the gods," often suspended public business and gave slaves a break. While ancient holidays like the Lupercalia pre-dated 509 BC, imperial anniversaries later gained prominence, and multi-day games (ludi) such as the Ludi Apollinares also offered days of celebration. Notably, the Saturnalia (December 17-23) is thought to have influenced Christmas customs like gift-giving. Beyond Rome, Buddhist festivals globally feature traditional cham dances or pagoda fairs, while Christianity's central festival, Easter, celebrates Jesus Christ's resurrection, though observance dates vary among traditions.