the math
If you wish to re-examine your old I Ching consultations using the Wild Crane system, a simple math formula will provide the Celestial Stem and Horary Branch for any western date: + +15 + B=C. "A" will be the last two digits of the year minus one. Example, 1989 will be written 89-1=88, so use 88 for "A." "B" is the total number of calendar days up to and including the date of your consultation (Beijing equivalent date of western style Gregorian calendar), from January 1st. For example, March 20th is 79th day of the year, July 15th is 196th day of the year. Note: February has 29 days in any leap year. This is for the 20th century. For the 21st century, add 100 to your "A" number. So year 2007 would be 107-1=106, so use 106. Use this formula to get initial answer "C." Divide "C" by 60; dispense with the whole number of answer; multiply the fraction of the answer by 60. This will result in the whole number (throw away the fraction here) that you use to find the Stem and Branch for your date. We can call this number "D." Take "D" and divide by 10. Throw away the resulting whole number and multiply the fraction by 10. This gives you the number of the Stem. Take "D" again and divide by 12. Throw away the whole part and multiply the fraction by 12. This gives you the Branch number. This formula may seem difficult, but with use it is simple. Practice first on current year dates, and compare your answers with the calendar that Alex has provided. A current example: 20 August 2007: <106X5> + <106 divided by 4=26.5, rounded off to 26> + 15 +232=803. Take 803 divided by 60=13.383. Throw away the 13 and multiply .383 by 60=23. Use 23 to get the Stem and Branch. For the Stem, 23 divided by 10=2.3. Throw away the whole 2 and multiply .3 by 10=3. So the Clestial Stem is 3 or III or Bing, whatever way you wish to write it. For the Branch, take 23 again, divide by 12=1.916. Throw away the whole one, and multiply the .916 by 12=11. So the Branch is 11, or Shu. An earlier example: 30 September 1986. This would be written out as 425 + 21 + 15 + 273 = 734. Take 734 divided by 60=12.23. Throw away the 12 and multiply .23 by 60=14. Use 14 to get the Stem and Branch. 14 divided by 10=1.4. Throw away the whole 1. .4 times 10 is 4 or IV or Ding. Then take 14 divided by 12=1.166. Throw away the whole 1 and multiply the .1666 by 12=1.999, or rounded to 2, which is chui. So Alex would write this IV c. I (Jia), II (Yi), III (Ping or Bing), IV (Ding), V (Wuh), VI (Ji), VII (Geng), VIII (Hsin), IX (Jen), X (Quei). These Celestial Stems are pairs of Wood, Fire, Earth, Metal, and Water.