January 1 is the first day of the year in the Gregorian calendar
" There are 364 days remaining until the end of the year (365 in leap years). The preceding day is December 31 of the previous year."
During the Middle Ages under the influence of the Christian Church, many countries moved the start of the year to one of several important Christian festivals — December 25 (the Nativity of Jesus), March 1, March 25 (the Annunciation), or even Easter. Eastern European countries (most of them with populations showing allegiance to the Orthodox Church) began their numbered year on September 1 from about 988.
In England January 1 was celebrated as the New Year festival, but from the 12th century to 1752 the year in England began on March 25 (Lady Day). So, for example, the Parliamentary record records the execution of Charles I occurring in 1648 (as the year did not end until March 24), although modern histories adjust the start of the year to January 1 and record the execution as occurring in 1649.
Most western European countries changed the start of the year to January 1 before they adopted the Gregorian calendar. For example, Scotland changed the start of the Scottish New Year to January 1 in 1600. England, Ireland and the British colonies changed the start of the year to January 1 in 1752. Later that year in September, the Gregorian calendar was introduced throughout Britain and the British colonies. These two reforms were implemented by the Calendar (New Style) Act 1750.
Holidays and observances
New Year's Day for many countries around the world using the Gregorian calendar; often celebrated at midnight with fireworks.
United States – Copyright Expiration Day, celebrating the expiration of the copyright of a year's worth of works of authorship into the public domain. Not celebrated from 1978 to 2018 because of repeated copyright term extensions.
Last day of Kwanzaa.
Cuba Liberation Day.
Czech Republic: Establishment of the Czech Republic.
Haiti Independence Day.
Slovakia: Establishment of the Slovak Republic.
Sudan Independence Day.
Republic of China: Establishment of the Republic of China
New Year's Day Parade in London, United Kingdom.
Vienna New Year's Concert.
Pasadena, California – the Tournament of Roses Parade and, traditionally, the Rose Bowl.
Christian celebrations: (edit)
The eighth day of Christmas (and eighth night of the same) in Western Christianity.
Anglican and Episcopal churches – Feast of the Holy Name of Jesus.
Roman Catholicism – Feast of the Circumcision (Old calendar).
Roman Catholicism – Holy Day of Obligation in many countries. Final Day of Octave of Christmas, Solemnity of Mary (New calendar).
Feast days of the following:
Fulgentius of Ruspe
January 1 (Eastern Orthodox liturgics)