What are the ancient fortune-telling materials?

What did people call birthdays in ancient times?

In ancient times, people called birthdays, which were transformed into four groups of heavenly stems and earthly branches according to three factors: date of birth, time of birth and place of birth. The eight characters are also called four columns, and one column corresponds to a group of branches.

For example, Anonymous was born on1986 August 23rd 14: 08 in Linli County, Changde City, Hunan Province. Using the online spelling tool, he found that his birthday was: Bing Yin Bing Yin Hai.