Folk Custom Almanac and

Author: Wang Junyun
Publisher:
Publish Date: 2006-10-01
Features:
1. The Origin of the Calendar
The use of the "calendar" is to distinguish seasons, record dates, and establish a standard for calculating time. In ancient times, people worked when the sun rose and rested when it set, making no need for a calendar. However, as humans gradually evolved and their relationships became more complex, there was a need for a unit of time as a benchmark. This unit must be based on a fixed phenomenon that has elapsed a certain amount of time and must be universally recognized. Thus, one day was taken as a day, which is the basic unit of most calendars: one lunar phase cycle as a month, forming the basis of the lunar calendar; and one cold and warm season as a year, forming the basis of the solar calendar.
2. The Evolution of the Calendar
It is said that the Yellow Emperor established the Heavenly Stems and Earthly Branches, Fu Xi created the Jia calendar, the Yellow Emperor ordered Da Nao to create the Jia Zi, Tai Hao established the calendar system, and Zhuan Xu created a new calendar. Emperor Yao ordered Xi He to diligently teach people the passage of time, setting three hundred and sixty-six days, using intercalary months to determine the four seasons and complete the year, which was roughly equivalent to the modern calculation of the tropical year. Xia Qi promulgated the Xia calendar, which became the sole standard for the Chinese calendar. The calendars of the Three Dynasties were different: Xia began the year with the month of Ren (the second month in the lunar calendar), Shang began the year with the month of You (the twelfth month in the lunar calendar), and Zhou began the year with the month of Zi (the twelfth month in the lunar calendar). Qin began the year with the month of Hai (the twelfth month in the lunar calendar), and in the early Han Dynasty, the calendar system remained unchanged from the Qin period. It was not until the time of Emperor Wu that the calendar was corrected to use the Xia calendar. Wang Mang changed to the Yin calendar, beginning with the month of You, but after the Wei Emperor, Emperor Wu of the Tang Dynasty, and Emperor Xuanzong, the calendar was adjusted multiple times, but it was soon reverted to the Xia calendar, which continued until the late Qing Dynasty. Ancient Western calendars were very chaotic. Ancient Greek calendars were similar to the old Chinese calendar and also used the lunar calendar. The Romans established a calendar with ten months, totaling 304 days. In 46 BC, Roman Emperor Julius Caesar ordered the reform of the calendar, which became the ancestor of the modern solar calendar. In 1582, Pope Gregory XIII further corrected the calendar, which is now used worldwide.
3. Solar and Lunar Calendars
The "solar calendar," also known as the "sun calendar," is based on the Earth's orbit around the sun, which is used by most Western countries and is also known as the "Western calendar." China adopted the solar calendar since the beginning of the Republic of China, hence it is also called the "national calendar." To distinguish it from the old Chinese calendar, it is also called the "new calendar." The "lunar calendar," also known as the "lunar calendar," is based on the moon's orbit around the Earth, with the year being the time it takes for the Earth to orbit the sun. In reality, it is equivalent to a combined solar and lunar calendar. Before the Republic of China era, China used this calendar, so to distinguish it from the current calendar, it is called the "old calendar." Most people think the lunar calendar is suitable for farmers and call it the "agricultural calendar," but this is not actually the case.
4. Three Types of Solar Years
The Earth's orbit around the sun takes 365 days, 6 hours, 9 minutes, and 9 seconds, known as the "sidereal year." The sun passes through the perihelion and moves eastward along the ecliptic for one orbit, returning to the perihelion, taking 365 days, 6 hours, 13 minutes, and 48 seconds, known as the "perihelion year." The sun passes through the vernal equinox, moves eastward along the ecliptic for one orbit, and returns to the vernal equinox, taking 365 days, 5 hours, 48 minutes, and 46 seconds, known as the "tropical year" or "year of the sun." Due to the westward movement of the equinoxes (vernal and autumnal equinoxes) along the ecliptic by about 50 seconds each year, the tropical year is shorter than the sidereal year by 20 minutes and 23 seconds, known as the "precession of the equinoxes." Since these three types of years have different durations, to keep the seasonal changes and climate cycles consistent each year, the tropical year is used as the basis for the calendar. People's understanding of the tropical year...