Is the birthday a lunar calendar or a solar calendar?

Birthday is the lunar calendar. In China's traditional calendar, the lunar calendar mainly refers to the calendar arranged according to the change of the moon phase cycle, while the solar calendar is based on the movement cycle of the earth around the sun. The lunar calendar refers to the tropic year of the sun and sets leap months to make its average calendar year adapt to the tropic year. It is a method of combining yin and yang by combining the lunar calendar with the solar calendar.

Birthday related content.

Is the year, month, day and hour of birth, expressed in heavenly stems and earthly branches. There are eight words in each column, so it is called eight characters. For example, when a person's constellations are Jiayin Year, New Yue Wei, Gui You Day and Guihai, we can see that birthdates is the time when a person was born, and each column is expressed by heavenly stems and earthly branches. Birthday is the date when we were born. Now we are commonly known as constellations. In the prediction of Zhouyi, the official name is: four pillars and eight characters.