December 31st is the Feast of San Silvestro the First (St. Sylvester I), Pope and Confessor. By happenstance, the day coincides with New Year's Eve and has become entwined with the year-end celebration. Admittedly, most of the popular traditions affiliated with La Festa di San Silvestro have more to do with the new year than with the Saint's day.
Typical New Year's Eve celebrations in southern Italy begin with dinner parties. What better way to ring in the New Year than with family and friends? Customarily lentils and pork sausages are served; it's said the food represents wealth and will bring luck and good fortune. Figs are also exchanged so the coming year will be sweet as well. Afterward, people gather around bonfires or get together in the streets and squares to socialize and party. At midnight they watch huge fireworks displays; the one in Naples is sheer pandemonium.
Source: Magna Grece