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.
The ancient Romans began their consular year on January 1, ever since 153 BC. 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.
