General Rule (1)

As Chinese Gender Chart was developed in China, it is not surprising that Chinese lunar calendar is used for gender prediction.

What is Lunar Calendar?
A lunar calendar is actually a calendar whose date indicates the moon phase. A lunar month is determined by the period required for the moon to complete its full phasic cycle of 29 and a half days, a standard that makes the lunar year a full 11 days shorter than its solar counterpart. This difference is made up every 19 years by the addition of seven lunar months, which is called leap month.

How to convert Gregorian (Western) Calendar to Chinese Lunar Calendar?
The following table covers the interval from 1931 to 2030, and by clicking on the years,
Gregorian-Lunar Camlendar Conversion Tables (in pdf), provided by Hong Kong Observatory, will be popped up. Following the tables, you can easily transfer the Gregorian date to lunar date, within this 100-year period.

1931	1932	1933	1934	1935	1936	1937	1938	1939	1940
1941	1942	1943	1944	1945	1946	1947	1948	1949	1950
1951	1952	1953	1954	1955	1956	1957	1958	1959	1960
1961	1962	1963	1964	1965	1966	1967	1968	1969	1970
1971	1972	1973	1974	1975	1976	1977	1978	1979	1980
1981	1982	1983	1984	1985	1986	1987	1988	1989	1990
1991	1991	1992	1993	1994	1995	1996	1997	1998	2000
2001	2002	2003	2004	2005	2006	2007	2008	2009	2010
2011	2012	2013	2014	2015	2016	2017	2018	2019	2020
2021	2022	2023	2024	2025	2026	2027	2028	2029	2030

Examples

a. What is the lunar date of Gregorian April 4, 1990?

Click on the year 1990 in the above table, and you can easily find out the corresponding lunar date is Day 9 of the 3rd Lunar Month.

b. What is the lunar date of Gregorian June 10, 1967?

Click on the year 1967 in the above table, and you can easily find out the corresponding lunar date is Day 3 of the 5th Lunar Month..

c. What is the lunar date of Gregorian Februray 2, 1988?

Click on the year 1988 in the above table, and you can find out the corresponding lunar date is Day 15 of the 12th Lunar Month of the previous lunar year. (Note: January 1st to Februray 16th of 1988 is considered as part of the previous lunar year. )

The rationale behind lunar calendar on gender prediction?
No one knows exactly how the ancient chinese could develop such highly accurate baby birth chart. But many people believe that the chart was created by utilizing the chinese five elements plus decade-long statistics.

In western countries, the effect of lunar month and mother's birth date on gender selection has not been carefully studied until 1950s, when Dr Eugen Jonas, a Czechoslovakian gynecologist, set up a fertility clinic and carried out scientifically controlled tests on thousands of women using this astrological method. His tests resulted in a consistent 98% accuracy. Dr. Jonas' method includes a belief that

The time of a woman's fertility depends on the recurrence of the angle of the sun and the moon that occurred at the woman's own birth. The sex of the child depends on the position of the moon at conception. Certain planetary configurations at the time of conception can effect the viability of the embryo.

Althought his theories can not really explain the rationale behind the chinese birth chart, he did mention that gender selection is related to woman's birth and lunar cycle.

For more about Jonas method, please visit
   - The Art & Science of Reflexology & Astrology    
   - http://www.menstruation.com.au/periodpages/lunarhistory.html

Now you can find out the gender of your (future) baby in seconds. No hassle! Let the computer find out your correct lunar age! click here