Is this a solar or lunar birthday? The horoscopes need to be arranged according to the birthday of the lunar calendar. The birth date or eight characters are actually another way of saying the four pillars in the Zhouyi terminology. The four pillars refer to the time of birth, namely year, month, day and hour.
Humans use one word each for heavenly stems and earthly branches to express year, month, day and time, such as Jiazi year, Bingshen month, Xinchou day...