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The traditional East Asian calendars divide a year into 24 solar terms (節氣). Qiūfēn (pīnyīn) or Shūbun (rōmaji) (Chinese and Japanese: 秋分; Korean: 추분; Vietnamese: Thu phân; literally: "autumnal equinox") is the 16^th solar term. It begins when the Sun reaches the celestial longitude of 180° and ends when it reaches the longitude of 195°. It more often refers in particular to the day when the Sun is exactly at the celestial longitude of 180°. In the Gregorian calendar, it usually begins around September 23 and ends around October 8.