In Korea, “Yuksipgapja” (sexagenary cycle) is one traditional way of expressing the year, month and day in the lunar calendar. Its basic concepts were originated from the idea of systematic and harmonious movements among 10 “Chon-gan” (Heavenly stems) and 12 “Ji-ji” (Earthy branches).

The 10 “Chon-gan” are gap, eul, byeong, jeong, mu, gi, gyeong, shin, im and gye. And the 12 “Ji-ji” are ja, chuk, in, myo, jin, sa, o, mi, shin, yu, sul and hae. To mark a calendar with these, you pick one element from each part, and make a sequential combination of the two.

For example, if one year is described as the year of “Gap-ja,” then the next year is “Eul-chuk” and after that is “Byeong-in.” This order repeats itself every 60 years because the least common multiple of 10 and 12 is 60. The same applies to months and days. But today this rule is often referred to only in the context of the........

© The Korea Times