What is "guyu"

The traditional East Asian calendars divide a year into 24 solar terms (節氣). Gǔyù ( pīnyīn) or more commonly pronounced as Gǔyǔ, Kokuu ( rōmaji), or Gogu ( romaja) 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.