It is the party that celebrates the beginning of a new year. The date on which this celebration takes place depends on the type of calendar used, and the most common is January 1, the Gregorian calendar, which was established by Pope Gregory XIII in 1582, and is used in most countries of the world. With the spread of Western culture to the rest of the world during the 20th century, January 1 became a universal date, even in countries with their own New Year celebrations.