Which period has the earliest record of New Year celebrations?

The earliest record of festivities in honor of new year's arrival date was 4,000 years ago to ancient Babylon in Mesopotamia (Iraq). For the Babylonians, the first moon following the vernal equinox (day in late March, where there is equal amount of sunlight and darkness) heralded as the start of new year. They marked the occasion with a massive religious festival called Akitu (derived from the Sumerian word for barley, which was cut in the spring) that involved a different ritual on each of its 11 days.

The early Roman calendar consisted of 10 months and 304 days, with each new year beginning at the vernal equinox; according to tradition, it was created by Romulus, the founder of Rome, in the eighth century B.C. A later king, Numa Pompilius, is credited with adding the months of Januarius and Februarius. Over the centuries, the calendar fell out of sync with the sun, and in 46 B.C. the emperor Julius Caesar decided to solve the problem by consulting with the most prominent astronomers and mathematicians of his time. He introduced the Julian calendar, which closely resembles the more modern Gregorian calendar that most countries around the world use today.

The Chinese New Year, for instance, also called Lunar New Year, is an annual 15-day festival in China and Chinese communities around the world that begins with the new moon that occurs sometime between January 21 and February 20 according to Western calendars. Festivities last until the following full moon.