NEW YEAR'S DAY:

January 1, 45 B.C.

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 45 B.C., making 46 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 before his
assassination in 44 B.C., he changed the name of the month Quintilis to Julius
(July) after himself. 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, a
11-minute-a-year error added seven days by the year 1000, and 10 days by the
mid-15th century.The Roman 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.