From ancient times China had two series of characters used for numbering (not for numbers!). One is the "ten stems" (jik-kan 十干), the other is the "twelve branches" (jûni-shi 十二支). They were combined to make a cycle of 60, the sexegenary cycle.These series spread over east and south-east Asia and were taken over by the Japanese from very early. They are still known in Japan, though since the [[Meiji period]] (1868-1912) their use has been very limited.
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From ancient times China had two series of characters used for numbering (not for numbers!). One is the "ten stems" (jik-kan 十干), the other is the "twelve branches" (jûni-shi 十二支). They were combined to make a cycle of 60, the sexegenary cycle. These series spread over east and south-east Asia and were taken over by the Japanese in the seventh century<ref>J. Edward Kidder, Jr. "Himiko and Japan's Elusive Chiefdom of Yamatai: Achaeology, History, and Mythology." University of Hawai'i Press: 2007, Page 187</ref>. They are still known in Japan, though since the [[Meiji period]] (1868-1912) their use has been very limited.