The Heavenly Stems are a traditional Chinese system used to represent time, particularly in calendars and astrology. There are ten stems, which are: Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, and Gui. These stems are often paired with the Earthly Branches to form a cycle that helps in tracking years, months, days, and even hours. This system is part of the larger Chinese calendar and is significant in various cultural practices, including feng shui and Chinese medicine. The combination of Heavenly Stems and Earthly Branches creates a 60-year cycle, which is essential for understanding traditional Chinese timekeeping and astrology.