The Chinese people have contributed many wonderful inventions to the world, including paper and print, gun-powder and even the compass, but one interesting discovery which occurred in Beijing approximately 750 years ago revealed a chart that is known today as the Chinese Pregnancy Calendar and also referred to as The Chinese Birth Calendar, "Baby Gender chart or Chinese Gender Calendar". The original colander can still be seen at the Beijing Institute of Science in China.
The pregnancy calendar is thought to have been created not to predict the gender of the already conceived baby but to give parents a way to choose their baby’s gender by conceiving their child at a certain time of year according to the age of the mother to be. Determining the sex of the baby was once very important to many parents in Chinas history and is still an issue to many Chinese people today where many men and women have a preference for the birth of male to that of a female. Such a strong desire to have baby boys that baby girls seems to be such a convincing reason for having a gender predicting calendar (The Chinese Pregnancy Calendar).
The Pregnancy Calendar works simply by calculating it's results based solely upon the ladies age and the month that she conceived, this is done by drawing two straight lines on the calander one horizontal relating to the woman's age and one vertical line representing the month of conception, the place where both lines meet shows the expected baby’s gender. No one could guarantee the accuracy of the predictions of this chart; however some people will say that it is extremely accurate. We reckon it is 50% right, so use it for fun only.