A person's Chinese age is an addition of either 1 or 2 years to the Gregorian calendar or actual age. If a person was born before the end of Chinese New Year, then 1 year is added. Two years are added for those people who were born after the new year.
The Gregorian calendar is also known as the English calendar. It is based on the sun's movements. The Chinese Lunar calendar, which makes reference to the Chinese New Year, is based on the moon's phases or movements.
The Chinese lunar chart, which is more than 700 years old, is used by many women to determine their unborn child's gender. It is based on a mother's Chinese or lunar age and the lunar month at the time of conception. The original chart is kept at Beijing's Science Institute.