Why are there solar and lunar calendars on the calendar?

Because both the solar calendar and the lunar calendar are common in our country.

1. The lunar calendar is one of the traditional Chinese calendars, also known as "Yin calendar", "Ancient calendar", Han calendar, "Huang calendar", "Xia calendar" and "Old calendar".

Strictly speaking, my country's traditional calendar should not be called the lunar calendar. It is a lunisolar calendar, which is now called the "Lunar Calendar". To be precise, it should be called the "Han Calendar". (This name is based on the rules of the "Han Calendar" proposed during the reign of Emperor Wu of the Han Dynasty, and the name of this calendar in the "Complete Collection of Han Calendar" compiled by Emperor Kangxi of the Qing Dynasty. The result is that this calendar has been called the "Han Calendar" since ancient times. "Calendar".)

The Han calendar uses the method of setting leap months and twenty-four solar terms, so that the average length of the calendar year is equal to the tropical year, so that it has the elements of the solar calendar. From this perspective, the Han calendar has its advantages. It better coordinates the cycles of the sun and the moon and achieves the unity of yin and yang. It is one of the most scientific astronomical calendars in the world.

2. Our country began to adopt the Gregorian calendar in 1912. The year after the Revolution of 1911 (1912), the then government of the Republic of China adopted the Gregorian calendar as the national calendar. In terms of chronology, the AD chronology was parallel to the Republic of China chronology.

On September 27, 1949, as approved by the First Plenary Session of the Chinese People’s Political Consultative Conference, the newly established People’s Republic of China adopted the Gregorian calendar and the AD that are commonly used by most countries in the international community. Calendar and chronology. However, the lunar calendar has not been abolished. Today's traditional Chinese festivals are still based on the lunar calendar.

Extended information

There are many methods of chronology in various countries around the world, including the chronology of stems and branches, Taoist calendar, imperial chronology, astronomical chronology, historical chronology, etc. In addition, there are Buddhist chronology, Islamic chronology, Jewish chronology, Japanese chronology, Greek chronology, etc.

In China, we had our own calendar as early as 4000 BC. Starting from the Yellow Emperor's calendar, for a long historical period, China has used the "Stem and Branch Calendar System", which combines the ten heavenly stems and the twelve earthly branches respectively, and every 60 years is a cycle. Up to now (2018), it is the traditional Chinese calendar Kaiyuan 4715.

Since the starting point of the AD chronology is AD 1, most scientists who have a full understanding of the AD chronology and most authoritative astronomical institutions in the world clearly support the statement that the 21st century began in 2001.

Baidu Encyclopedia - Lunar Calendar

Baidu Encyclopedia - A.D.