There are two ways of calculating the full moon of a child, one is according to the lunar calendar, and the other is according to a 30-day cycle. 1. Calculation according to the lunar calendar: According to the lunar calendar, the full moon will be calculated from the day of the child’s birth to the same day of the next month. If the child is born on the eighth day of February, the child’s full moon will be on the eighth day of March. This calculation does not take into account the specific elapsed time, such as February although less than 30 days, but the child is still full moon. 2. Calculation by 30 days: Calculated according to a 30-day cycle, the day of birth is usually taken as the first day, and the 30th day is the full moon. This is a more accurate way of calculating the full moon than the lunar calendar, and there is usually no undercounting or overcounting. Both ways of calculating a child’s full moon are commonly seen in our daily lives.