Conversion of AD years to Chinese zodiac years.

The traditional Chinese calendar system is based on a combination of solar and lunar cycles and is often referred to as the lunisolar calendar. It uses a 60-year cycle called the sexagenary cycle, or the Stems-and-Branches system, which combines ten heavenly stems with twelve earthly branches to form 60 unique combinations. Each sexagenary cycle starts with a unique combination of one heavenly stem and one earthly branch, which is known as a Stem-Branch or Gan-Zhi. The first year of the sexagenary cycle is represented by the combination of Jia (Yang Wood) and Zi (Rat), which corresponds to the year 1984 in the Western calendar. To convert a Western calendar year to the corresponding Chinese lunar year, you need to find the Stem-Branch combination for that year and determine the starting day of the Chinese New Year for that cycle.