The traditional East Asian calendars divide a year into 24 solar terms. Qiūfēn, Shūbun, Chubun, or Thu phân is the 16th 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.