Another unusual coin from the "Ancient Calendars" series. 62.2 g of pure silver, exceptionally beautiful relief with a clear, high relief. Packed in a thematic box with equally beautiful graphics. Limited to 500 copies only! The heavenly stems (or ten trunks) are a ten-stage cyclic system used in Chinese philosophy, alchemy and astrology. Together with earthly branches they form a sixty-year cycle, used in Chinese traditional calendars and in astrology. In philosophy they are closely connected with the concepts of yin and yang and the theory of five elements. Earth branches are a Chinese system used to measure time. It is based on astronomical observations of Jupiter's movement. Since the cycle of circulation of this planet around the Sun is approximately 12 years (exactly 11.86 years), the Chinese divided the ecliptic into 12 sections and called Jupiter itself Suìxīng or the Annual Star. Each of the 12 years of the cycle corresponded to one symbol in the system of Earthly Branches. In a similar way the year was divided into 12 months. To make it easier to remember, the 12 Earthly Branches were assigned 12 animals of the Chinese Zodiac.  The Earthly Branches are currently used with the system of Heavenly Stems. Together with it, they make up the traditional Chinese calendar and the so-called sixty-year cycle.