Qīngmíng, Seimei, Cheongmyeong or Thanh minh, is the name of the 5th solar term of the traditional Chinese lunisolar calendar,[1] which divides a year into 24 solar terms (t. 節氣/s.
[2] In space partitioning, Qingming begins when the sun reaches the celestial longitude of 15° and ends when it reaches the longitude of 30°.
It more often refers in particular to the day when the sun is exactly at the celestial longitude of 15°, usually on April 5.
[3] Compared to the space partitioning theory, in the time division theory Qingming falls around April 7 or approximately 106.5 days after winter equinox.
Each solar term can be divided into 3 pentads (候).