Guyu Explained

The traditional Chinese lunisolar calendar divide a year into 24 solar terms.^[1] Gǔyǔ, Kokuu, Gogu, or Cốc vũ is the 6th solar term. It begins when the Sun reaches the celestial longitude of 30° and ends when it reaches the longitude of 45°. It more often refers in particular to the day when the Sun is exactly at the celestial longitude of 30°. In the Gregorian calendar, it usually begins around April 20 and ends around May 5.

Traditionally, Guyu marks the beginning of warmer temperatures and the onset of the rainy season, making it an important period for farmers to ensure a satisfactory harvest for the rest of the year.

Pentads

Each solar term can be divided into 3 pentads (候). They are: first pentad (初候), second pentad (次候) and last pentad (末候). Pentads in Guyu include:

China

• First pentad: 萍始生, 'Duckweed begins to sprout'.^[2]
• Second pentad: 鳴鳩拂其羽, 'Cuckoo shakes off wings'.^[2]
• Last pentad: 戴勝降于桑, 'Hoopoe perches in mulberry trees'.^[2]

Japan

• First pentad:, 'Reed begins to bud'.^[3]
• Second pentad:, 'Frost ends and rice seedlings to grow'.^[3]
• Last pentad:, 'Peony blooms'.^[3]

Notes and References

1. Zhang . Peiyu . Hunag . Hongfeng . The Twenty-four Solar Terms of the Chinese Calendar and the Calculation for Them . Purple Mountain Observatory . 1994 . March 9, 2021 . June 12, 2021 . https://web.archive.org/web/20210612151759/https://en.cnki.com.cn/Article_en/CJFDTotal-GXKK403.013.htm . dead .
2. Book: 新加纂録類 (Shinka Sanrokurui) . 改定史籍集覧 (Kaitei Shiseki Shūran) . 19 . Kondō Heijō (近藤瓶城) . 110 . 近藤活版所 (Kondō Kappansho) . Tokyo . 1901 . (Meiji 34) .
3. Book: 図説日本民俗学全集 (Zusetsu Nihon Minzokugaku Zenshū) . 年中行事編 (Nenjū Gyōjihen) . Fujisawa Morihiko. 7 . 103 . Akane Shobō . 1961 . Tokyo .