section_path: Abstract
section_name: Abstract
paragraph_text: The traditional Chinese calendar, dating back to the Han dynasty, is a lunisolar calendar that blends solar, lunar, and other cycles for social and agricultural purposes. While modern China primarily uses the Gregorian calendar for official purposes, the traditional calendar remains culturally significant. It determines the timing of Chinese New Year with traditions like the twelve animals of the Chinese Zodiac still widely observed.
  
  The traditional Chinese calendar uses the sexagenary cycle, a repeating system of Heavenly Stems and Earthly Branches, to mark years, months, and days. This system, along with astronomical observations and mathematical calculations, was developed to align solar and lunar cycles, though some approximations are necessary due to the natural differences between these cycles. Over centuries, the calendar was refined through advancements in astronomy and horology, with dynasties introducing variations to improve accuracy and meet cultural or political needs.
  
  While the Gregorian calendar has become now standard for civic daily use in China, the traditional lunisolar calendar continues to influence festivals, cultural practices, and zodiac-based customs. Beyond China, it has shaped other East Asian calendars, including the Korean, Vietnamese, and Japanese lunisolar systems, each adapting the same lunisolar principles while integrating local customs and terminology.
  
  Epochs, or fixed starting points for year counting, have played an essential role in the Chinese calendar's structure. Some epochs are based on historical figures, such as the inauguration of the Yellow Emperor (Huangdi), while others marked the rise of dynasties or significant political shifts. This system allowed for the numbering of years based on regnal eras, with the start of a ruler's reign often resetting the count.
  
  The Chinese calendar also tracks time in smaller units, including months, days, and double-hour periods called shichen. These timekeeping methods have influenced broader fields of horology, with some principles, such as precise time subdivisions, still evident in modern scientific timekeeping. The continued use of the calendar today highlights its enduring cultural, historical, and scientific significance.