New Year is the time at which a new calendar year begins and the calendar's year count is incremented. In many cultures, the event is celebrated in some manner.^[1] The New Year of the Gregorian calendar, today in worldwide use, falls on 1 January, as was the case with the Roman calendar. There are numerous calendars that remain in regional use that calculate the New Year differently.

The order of months in the Roman calendar was January to December since King Numa Pompilius in about 700 BC, according to Plutarch and Macrobius. According to Catholic tradition, 1 January is the day of the circumcision of Jesus (on the eighth day from his birth), when the name of Jesus was given to him (Luke 2:21).

It was only relatively recently that 1 January again became the first day of the year in Western culture. Until 1751 in England and Wales (and all British dominions) the new year started on 25 March – Lady Day, one of the four quarter days (the change to 1 January took place in 1600 in Scotland).^[2] Since then, 1 January has been the first day of the year. During the Middle Ages several other days were variously taken as the beginning of the calendar year (1 March, 25 March, Easter, 1 September, 25 December).^{[citation needed][where?]} In many countries, such as the Czech Republic, Italy and the UK, 1 January is a national holiday.

For information about the changeover from the Julian calendar to the Gregorian calendar and the effect on the dating of historical events etc., see Old Style and New Style dates.

With the expansion of Western culture to many other places in the world during recent centuries, the Gregorian calendar has been adopted by many other countries as the official calendar, and the 1 January date of New Year has become global, even in countries with their own New Year celebrations on other days (such as China and India). In the culture of Latin America there are a variety of traditions and superstitions surrounding these dates^{[clarification needed]} as omens for the coming year. The most common modern dates of celebration are listed below, ordered and grouped by their appearance relative to the conventional Western calendar.

By month or season[link]

January[link]

Baby New Year 1905 chases old 1904 into the history books in this cartoon by John T. McCutcheon.

• 1 January: The first day of the year in the Gregorian calendar used by most countries. Eight of the twelve biggest Eastern Orthodox Churches which have adopted the Revised Julian calendar – Bulgaria, Cyprus, Egypt, Greece, Romania, Syria, and Turkey – also celebrate 1 January as the New Year.
• 7 January: This is the Ethiopian Orthodox New Year holiday.
• In the Eastern Orthodox Church, the civil New Year falls on Gregorian 14 January (1 January in the Julian calendar). Many in the countries where Eastern Orthodoxy predominates celebrate both the Gregorian and Julian New Year holidays, with the Gregorian day celebrated as a civic holiday, and the Julian date as the "Old New Year", a religious holiday. The orthodox churches of Georgia, Jerusalem, Russia, the Republic of Macedonia, Serbia and Ukraine still use the Julian Calendar.
• The Chinese New Year, also known as the Lunar New Year, occurs every year on the new moon of the first lunar month, about four to eight weeks before spring (Lichun). The exact date can fall any time between 21 January and 21 February (inclusive) of the Gregorian Calendar. Traditionally, years were marked by one of twelve Earthly Branches, represented by an animal, and one of ten Heavenly Stems, which correspond to the five elements. This combination cycles every 60 years. It is the most important Chinese celebration of the year.
• The Vietnamese New Year is the Tết Nguyên Đán which is for most times the same day as the Chinese New Year.
• The Tibetan New Year is Losar and falls from January through March.