With the calculation of the movement time of the solar ecliptic cycle and the need to determine the beginning of the year, the tradition of using the winter solstice as the starting point of the astronomical year gradually formed, which made the use of the table to determine the time when the sun reached the winter solstice point the key to the length of the return year. However, the winter solstice does not always occur in the middle of the day, it can occur at any time of the day, so in order to find the exact time of the winter solstice, the ancients had to carry out continuous long-term calculations of the winter solstice shadow.
The number of days from the winter solstice of a certain year to the winter solstice of the following year is called "year", which is the so-called "flat solar year", but this number of days is not an integer, but has odd zeros. Therefore, the shadow of the sun at noon on the winter solstice of a certain year cannot coincide with the shadow of the day at noon of the winter solstice of the previous year and the year after. The ancients observed for four consecutive years and found that the shadow of the sun at noon on the winter solstice gradually returned to its original place and overlapped, so it was known that the shadow of the sun on the fourth year, that is, 1461, returned to its original place (overlapped), and divided by four, the number of days in a year was 36525th. This value is very close to the 365 that is accurately measured today2425 can be used as the most basic core value to make a calendar. This is odd zero per year at 0The 25th is a quarter of a day, and the ancient name of the "quarter calendar" refers to this.
As one of the sources of traditional Chinese culture, Yixue is still of great significance in today's society. The study of Yixue not only covers the inheritance and development of knowledge in astronomical calendars and solar terms, but also pays attention to the harmonious relationship between human beings and nature, and between humans and society. By revealing the connections and regularities between things, Yixue helps individuals to know themselves, understand others, and grasp opportunities, and in this way, promote personal development and social progress.
In order to better promote Yixue culture and improve the public's awareness of the level of traditional Chinese culture, the Yixue Cultural Proficiency Test came into being. This exam is designed to test an individual's understanding of easy-to-learn knowledge and theories, and to help individuals improve their own knowledge. By taking the exam, individuals can better understand themselves, grasp their opportunities, and reach their greater potential in work and life.
As an authoritative and professional examination in the field of traditional Chinese culture, the Yixue Cultural Proficiency Test will be held nationwide with the help of advanced scientific and technological means. We invited a number of experts in the field of easy learning to participate in the preparation of exam questions, and organized several rounds of rigorous evaluation and gatekeeping process. The content of the exam covers easy-to-learn theories, calendar knowledge, solar terms, etc., and focuses on testing candidates' ability to solve practical problems and apply theories.
Participating in the easy-to-learn cultural proficiency test can not only expand one's knowledge and way of thinking, but also improve one's overall quality and coping ability. We believe that the Yixue Cultural Proficiency Test will be an important step in promoting the development and inheritance of traditional Chinese culture.