The New Year is the time or day at which a new calendar year begins and the calendar's year count increments by one. Many cultures celebrate the event in some manner. [1] In the Gregorian calendar, the most widely used calendar system today, New Year occurs on January 1 (New Year's Day, preceded by New Year's Eve). This was also the first day of the year in the original Julian calendar and the Roman calendar (after 153 BC). [2] Other cultures observe their traditional or religious New Year's Day according to their own customs, typically (though not invariably) because they use a lunar calendar or a lunisolar calendar. Chinese New Year, the Islamic New Year, Tamil New Year (Puthandu), and the Jewish New Year are among well-known examples. Iranian New Year begins at the March equinox. India, Nepal, Greece and other countries also celebrate New Year on dates according to their own calendars that are movable in the Gregorian calendar. During the Middle Ages in Western Europe, while the Julian calendar was still in use, authorities moved New Year's Day, depending upon locale, to one of several other days, including March 1, March 25, Easter, September 1, and December 25. Since then, many national civil calendars in the Western World and beyond have changed to using one fixed date for New Year's Day, January 1-most doing so when they adopted the Gregorian calendar. The Chinese New Year, also known as Spring Festival or Lunar New Year, occurs every year on the new moon of the first lunar month, about the beginning of spring (Lichun). The exact date can fall any time between January 21 and February 21 (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 Korean New Year is a Seollal or Lunar New Year's Day. Although January 1 is, in fact, the first day of the year, Seollal, the first day of the lunar calendar, is more meaningful for Koreans. A celebration of the Lunar New Year is believed to have started to let in good luck and ward off bad spirits all throughout the year. With the old year out and a new one in, people gather at home and sit around with their families and relatives, catching up on what they have been doing.