What is the connection between the Eight Diagrams of the Book of Changes and birthdays?

Eight diagrams are symbols in the Book of Changes, and eight characters are your birthday. Calculate your birthday for the horoscope, the ancient time-keeping method in China. For example, this year is the Year of the Rabbit, so it is called the Year of the Rabbit. I forgot too. You can turn to the calendar. Twelve hours a day in sixty-one weeks: ugly, ugly, ugly, ugly, ugly, ugly, ugly, ugly, ugly, ugly, ugly, ugly, ugly.