In the Gregorian calendar, New Year's Eve, also known as Old Year's Day, is the evening or the entire day of the last day of the year, 31 December. In many countries, New Year's Eve is celebrated with dancing, eating, drinking, and watching or lighting fireworks. Some Christians attend a watchnight service. The celebrations generally go on past midnight into New Year's Day, 1 January.

Fireworks are a class of low explosive pyrotechnic devices used for aesthetic and entertainment purposes. They are most commonly used in fireworks displays, combining a large number of devices in an outdoor setting. Such displays are the focal point of many cultural and religious celebrations, though mismanagement could lead to fireworks accidents.