What is the relationship between solar terms, calendars and traditional festivals?

To clarify the relationship between solar terms, calendars and traditional festivals, we can't help but say that China's unique method of chronology is the method of chronology of cadres and branches. We are all familiar with the names of historical events, such as the Reform Movement of 1898 and the Revolution of 1911. Wu Jia, the Reform Movement of 1898, Xinhai, etc. are all names of years, and this method of describing years is called "chronology of cadres and branches".