Among the world's myriad cultures and their associated calendars, the idea of a "New Year" is relative and hardly specifies a universal celebration or even a universal point in time. Ways of celebrating the New Year range from the observances of religious rituals and superstitions to social gatherings featuring particular foods, music, dancing, noisemaking, fireworks and drinking.

This first encyclopedia devoted exclusively to the New Year includes 320 entries that give a global perspective on the New Year, beyond its traditional Western associations with Christmas. National or regional entries detail the principal traditions and customs of 130 countries, while 27 entries discuss major calendar systems in current use or of significant historical interest. The remaining entries cover a wide variety of subjects including literary works, movies, and television specials; the customs of specific ethnic groups; universal customs such as toasting and drinking; football bowl games and parades; and the New Year celebrations at the White House and the Vatican.