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.