Japanese Meanings: Youbi (曜日) and Shichiyou (七曜)

Recently, I have learned from Japanese Wikipedia that the names of the days of the week, or “Youbi (曜日: day of the week)”, that is, “Nichi-Youbi (日曜日: Sunday)”, “Getsu-Youbi (月曜日: Monday)”, “Ka-Youbi (火曜: Tuesday), “Sui-Youbi (水曜日: Wednesday)”, “Moku-Youbi (木曜日: Thursday)”, “Kin-Youbi (金曜日: Friday)”, and “Do-Youbi (土曜日: Saturday)”, comes from “Shichiyou (七曜)”.

What is Shichiyou in Japanese?

Originated from ancient Chinese astronomy, “Shichiyou (七曜)” is the word for the seven celestial bodies, “Taiyou (太陽: Sun)”, “Tsuki (月: Moon)”, “Ka-Sei (火星: Mars)”, “Sui-Sei (水星: Mercury)”, “Moku-Sei (木星: Jupiter)”, “Kin-Sei (金星: Venus)”, and “Do-Sei (土星: Saturn)”. In the Japanese word “Shichiyou (七曜)”, “Shichi (七)” is the Chinese character or Kanji for 7, while “You (曜)” refers to luminaries.

By the way, in Japanese, the sun is also called “Ohisama (お日様)”, in which “Hi (日)” stands for the sun, while the prefix “O (お)” and the suffix “Sama (様)” are Japanese honorifics. And the Kanji characters for the sun and the moon, “日” and “月” are also pronounced as “Nichi” and “Getsu” respectively.

Youbi is based on Shichiyou

Japanese Calendar

As you can notice by now, Youbi is based on Shichiyou, and it is believed that

  • “Nichi-Youbi (日曜日: Sunday)” is the day guarded by “Ohisama (お日様: Sun)”,
  • “Getsu-Youbi (月曜日: Monday)” is the day guarded by “Tsuki (月: Moon)”,
  • “Ka-Youbi (火曜日: Tuesday)” is the day guarded by “Ka-Sei (火星: Mars)”,
  • “Sui-Youbi (水曜日: Wednesday)” is the day guarded by “Sui-Sei (水星: Mercury)”,
  • “Moku-Youbi (木曜日: Thursday)” is the day guarded by “Moku-Sei (木星: Jupiter)”,
  • “Kin-Youbi (金曜日: Friday)” is the day guarded by “Kin-Sei (金星: Venus)”,
  • “Do-Youbi (土曜日: Saturday)” is the day guarded by “Do-Sei (土星: Saturn)”.

(Reference Pages: Wikipedia 七曜, 曜日 )


Hi, I'm Tomo, a Japanese blogger living in Niigata Prefecture, Japan. For the purpose of enriching your life, I would like to introduce things about Japan on this blog, especially unique Japanese products, cooking recipes, cultures, and facts and trivia.

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