Hello, when predicting the birth date of Zhouyi, you need to have "great luck", and this "great luck" often does not start from birth. Some people start great luck from the age of 10. In the past, it was not included in the Grand Luck and could not start, which is usually said to have not "taken root". Therefore, the "child's luck" between birth and the start of luck was needed to assist in fortune-telling. This is child luck.