Autumn Equinox (Qiufen) 秋分
The solar term
On the autumn equinox the sun is back over the equator and day and night are almost equal; it is also the midpoint of autumn's ninety days. From here on, nights in the northern hemisphere are longer than days. Since 2018 the day has also been China's Farmers' Harvest Festival.
| Year | Autumn Equinox |
|---|---|
| 2026 | September 23 |
| 2027 | September 23 |
| 2028 | September 22 |
| 2029 | September 23 |
| 2030 | September 23 |
Dates are for China time (UTC+8); in other time zones the term may fall on a different day.
The three pentads
Each solar term lasts about fifteen days and is divided into three pentads of five days, each named after a sign in nature. In 2026:
Thunder withdraws its voice 雷始收聲from September 23
Thunder falls quiet. Thunder was thought to come from yang; as yin grows after the equinox, it withdraws, the mirror of thunder's return at the spring equinox.
Insects seal their burrows 蟄蟲坯戶from September 28
Insects preparing to hibernate crawl into their burrows and seal the entrance with fine earth.
Waters begin to dry 水始涸from October 3
Rain grows scarce, and rivers, lakes and marshes begin to dry.
Hexagrams
In the table of the Tang monk Yixing’s Dayan calendar (recorded in the New Book of Tang), the three pentads of Autumn Equinox belong to three hexagrams:
- first pentad22 Bi (Adornment)Duke
- second pentad20 Guan (Contemplation)Sovereign
- third pentad54 Guimei (The Marrying Maiden)Marquis
The second, Guan (Contemplation), is one of the twelve sovereign hexagrams (十二辟卦), which trace the waxing and waning of yin and yang through the year. It stands for the eighth month of the traditional calendar: four yin lines below, yin grown strong.
Separately, the twenty-four lines of Kan, Zhen, Li and Dui govern the twenty-four solar terms in turn; Autumn Equinox belongs to Dui, nine at the beginning.
The hexagram calendar marks the season. It says nothing about fortune and has no bearing on a hexagram you cast. See sources and method.