The traditional Chinese calendar divides a year into 24 solar terms.
[1] Xiǎohán, Shōkan, Sohan, or Tiểu hàn (Chinese and Japanese: 小寒; pinyin: xiǎohán; rōmaji: shōkan; Korean: 소한; romaja: sohan; Vietnamese: tiểu hàn; lit.
'minor cold') is the 23rd solar term.
It begins when the Sun reaches the celestial longitude of 285° and ends when it reaches the longitude of 300°.
It more often refers in particular to the day when the Sun is exactly at the celestial longitude of 285°.