3. The Meaning of the Year 663 in East Asian Astronomy

If the trifunctional system is the principle of cosmic change in the East—that is, the fundamental principle of the Book of Changes, the Three Powers, and the Five Phases—then it connects to the question of what grounds the origin of the calendrical system of the ten heavenly stems and twelve earthly branches, which is the concentration of the Book of Changes, the Three Powers, and the Five Phases, actually possesses.

In contrast to Western astronomy, East Asian astronomy has the characteristic that each date carries a ganji rather than a constellation. For example, May 16, 2015, the reference date of this presentation, is the Eulmi year, Sinsa month, and Imjin day. The ganji of East Asian astronomy does not signify only the date; it serves as the standard for all affairs, including the study of fate (Myeongni), traditional medicine, and politics.

There are two methods for verifying whether the ganji assigned to a date by East Asian astronomy is valid: the method of verifying whether it is correct by actually applying it, and the method of verifying what the very first origin was. Since the former can be known through countless instances of history, it is set aside, and this paper examines the second method.

The second method ultimately becomes the question of when the first Gapja year, Gapja month, Gapja day, and Gapja hour occurred, and of what that day was based on. Although countless East Asian astronomers have studied East Asian astronomy for ages, it is only in today's age of advanced IT technology that it has been revealed that midnight at the winter solstice of 663 was the first Gapja year, Gapja month, Gapja day, and Gapja hour. To be precise, by the principle of the calendrical system it is not the Gapja year, Gapja month, Gapja day, and Gapja hour, but the Gyehae year, Gapja month, Gapja day, and Gapja hour.^[9]

By the principle of complexity science, this day neither repeats nor occurs more than once in human history. The phenomenon in the sky on this day was Oseongchwiru, the gathering of the five planets of the solar system into one. And the record closest to that day is the Battle of Baekchon River and the rise of Islam. Furthermore, 600 years later came Kublai Khan's founding of the Yuan dynasty; 1,200 years later was 1863, when Choe Su-un of Donghak was martyred; and 60 years after that was 1924, when one won (元) of the sixty-Gapja cycle came to a close.