New Year's Eve is on December 31, the final day of the Gregorian year, and the day before New Year's Day.

New Year's Eve is a separate observance from the observance of New Year's Day. In 21st-century Western practice, New Year's Eve is celebrated with parties and social gatherings spanning the transition of the year at midnight.

Many cultures use fireworks and other forms of noise making in part of the celebration. Some of the cities most well-known for their celebrations include Edinburgh, Sydney, Toronto, Moscow, Tokyo, Hong Kong, London, Berlin, Rio de Janeiro, Paris, and New York City.

New Year's Eve is a public non-working holiday in the following countries, among others: Argentina, Brazil, Mexico, Greece, the Philippines, and Venezuela.