Why Does the New Year Start on January 1?
In many countries the New Year begins on January 1. However, this wasn’t always the case. In fact, for centuries, other dates marked the start of the calendar, including March 25 and December 25. So how did January 1 become New Year’s Day We can partly thank the Roman king Numa Pompilius. According to tradition, during his reign (c. 715–673 BCE) Numa revised the Roman republican calendar so that January replaced March as the first month. It was a fitting choice, since January was named after Janus, the Roman god of all beginnings; March celebrated Mars, the god of war. (Some sources claim that Numa also created the month of January.) However, there is evidence that January 1 was not made the official start of the Roman year until 153 BCE. In 46 BCE Julius Caesar introduced more changes, though the Julian calendar, as it became known, retained January 1 as the year’s opening date. With the expansion of the Roman Empire, the use of the Julian calendar also spread. However, following the fall of Rome in the 5th century CE, many Christian countries altered the calendar so that it was more reflective of their religion, and March 25 (the Feast of the Annunciation) and December 25 (Christmas) became common New Year’s Days. It later became clear that the Julian calendar required additional changes due to a miscalculation concerning leap years. The cumulative effect of this error over the course of several centuries caused various events to take place in the wrong season. It also created problems when determining the date of Easter. Thus, Pope Gregory XIII introduced a revised calendar in 1582. In addition to solving the issue with leap years, the Gregorian calendar restored January 1 as the start of the New Year. While Italy, France, and Spain were among the countries that immediately accepted the new calendar, Protestant and Orthodox nations were slow to adopt it. Great Britain and its American colonies did not begin following the Gregorian calendar until 1752. Before then they celebrated New Year’s Day on March 25. Over time non-Christian countries also began to use the Gregorian calendar. China (1912) is a notable example, though it continued to celebrate the Chinese New Year according to a lunar calendar. In fact, many countries that follow the Gregorian calendar also have other traditional or religious calendars. Some nations never adopted the Gregorian calendar and thus start the year on dates other than January 1. Ethiopia, for example, celebrates its New Year (known as Enkutatash) in September.
In 45 B.C., New Year’s Day is celebrated on January 1 for the first time in history as the Julian calendar takes effect.
Soon after becoming Roman dictator, Julius Caesar decided that the traditional Roman calendar was in dire need of reform. Introduced around the seventh century B.C., the Roman calendar attempted to follow the lunar cycle but frequently fell out of phase with the seasons and had to be corrected. In addition, the pontifices, the Roman body charged with overseeing the calendar, often abused its authority by adding days to extend political terms or interfere with elections.
In designing his new calendar, Caesar enlisted the aid of Sosigenes, an Alexandrian astronomer, who advised him to do away with the lunar cycle entirely and follow the solar year, as did the Egyptians. The year was calculated to be 365 and 1/4 days, and Caesar added 67 days to 46 B.C., making 45 B.C. begin on January 1, rather than in March. He also decreed that every four years a day be added to February, thus theoretically keeping his calendar from falling out of step. Shortly after Caesar was assassinated in 44 B.C., Mark Anthony changed the name of the month Quintilis to Julius (July) to honor him. Later, the month of Sextilis was renamed Augustus (August) after his successor.
Celebration of New Year’s Day in January fell out of practice during the Middle Ages, and even those who strictly adhered to the Julian calendar did not observe the New Year exactly on January 1. The reason for the latter was that Caesar and Sosigenes failed to calculate the correct value for the solar year as 365.242199 days, not 365.25 days. Thus, an 11-minute-a-year error added seven days by the year 1000, and 10 days by the mid-15th century.
The Church became aware of this problem, and in the 1570s Pope Gregory XIII commissioned Jesuit astronomer Christopher Clavius to come up with a new calendar. In 1582, the Gregorian calendar was implemented, omitting 10 days for that year and establishing the new rule that only one of every four centennial years should be a leap year. Since then, people around the world have gathered en masse on January 1 to celebrate the precise arrival of the New Year.