Why use the solar calendar to approve the eight characters?

China matched ancient heavenly stems and earthly branches with foreign solar calendars, that is, solar calendars, because compared with lunar calendars, solar calendars are more accurate and stable. Only one month in every four years is February, and the lunar calendar is calculated according to the moon, which has many defects, such as two months in July of a year are calculated according to the lunar calendar, and so on! And heavenly stems and earthly branches corresponding to the solar calendar, you can get a very regular time!