Astrological sign operate on cycles of years, lunar months, and two-hour periods of the day (also known as "shichen"). A particular feature of the Chinese zodiac is its operation in a 60-year cycle in combination with the Five Phases of Chinese astrology (Wood, Fire, Metal, Water and Earth). Nevertheless, some researches say that there is an obvious relationship between the Chinese 12-year cycle and zodiac constellations: each year of the cycle corresponds to a certain disposal of Jupiter. For example, in the year of Snake Jupiter is in the Sign of Gemini, in the year of Horse Jupiter is in the Sign
Zodiac tropical zodiac used in Western astronomy and astrology, this means that the tropical "sign" of Aries currently lies somewhere within the "constellation" Pisces ("Age of Pisces"). The sidereal coordinate system takes into account the ayanamsa, "ayan" meaning "transit" or "movement", and "amsa" meaning "small part", i.e. movement of equinoxes in small parts. It is unclear when Indians became aware of the precession of the equinoxes, but Bhaskar II's 12th-century treatise "Siddhanta Shiromani" gives equations for measurement of precession of equinoxes, and says his equations are based on some lost equations of "Suryasiddhanta" plus the equation of Munjaala. The discovery of