Dahan (solar term)
Source: JPL Horizons On-Line Ephemeris System
The traditional East Asian calendars divide a year into 24 solar terms (節氣). Dàhán (pīnyīn), Daikan (rōmaji), or Daehan (romaja) (Chinese and Japanese: 大寒;Korean: 대한;Vietnamese:Đại hàn;literally: "major cold") is the 24th solar term. It begins when the Sun reaches the celestial longitude of 300° and ends when it reaches the longitude of 315°. It more often refers in particular to the day when the Sun is exactly at the celestial longitude of 300°. In the Gregorian calendar, it usually begins around 20 January and ends around 4 February.