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. 节气).^[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. In the Gregorian calendar, it usually begins around 4 or 5 April and ends around 20 April.

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 Qingming include:

China

• First pentad: 桐始華/桐始华, 'The paulownia begins to bloom'.
• Second pentad: 田鼠化為鴽/田鼠化为鴽, 'Voles(you) transform into quails'.
• Last pentad: 虹始見/虹始见, 'Rainbows begin to appear'.

Japan

• First pentad: 玄鳥至 (tsubame itaru), 'The swallow flies back from the south'.
• Second pentad: 鴻雁北 (kōgan kitae kaeru), 'The goose migrates to the north'.
• Last pentad: 虹始見 (niji hajimete arawaru), 'Rainbows begin to appear in the sky after shower'.