Why should fortune-telling be calculated according to beginning of spring?
The beginning of spring you mentioned is the calendar of the first day of the first month, which has existed in history. This calendar was formulated by Shen Kuo, a scientist in the Northern Song Dynasty. It is a solar calendar, with beginning of spring, Jing Zhe and Qingming as the first days of January, February and March respectively. However, this calendar has not been implemented. Later, in the Taiping Heavenly Kingdom, a calendar of 14 years was implemented, which was similar to the Qi Twelve Calendars.
Although the "Twelve Calendars of Qi" was not implemented, it had a certain impact on later generations-some folk activities took beginning of spring, Jing, Zhe, Han Xiao as the first day of the first month, and the twelfth month of February as the second day of the first month.
One thing needs to be explained: from the birth of the summer calendar (lunar calendar) to the present, the first day of the first month and beginning of spring are not the same day (except that it happens to be the same year), and it is not a historical reason to separate them!