The traditional Chinese lunisolar calendar divide a year into 24 solar terms. 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.