Liqiu (立秋) — Beginning of Autumn

Liqiu occurs at celestial longitude 135°, around August 7-9. The astronomical start of autumn in the traditional almanac. Metal element strengthens; yin energy begins to take over.

Tradition: "biting autumn" (咬秋) — eating watermelon to ward off lingering summer heat; weighing oneself to compare with summer. Climate: heat continues but mornings/evenings cool noticeably; "autumn tiger" (秋老虎) heat waves are common.

The four “establishing” terms — Lichun, Lixia, Liqiu and Lidong — together with the two solstices and two equinoxes make up the eight nodes, the oldest layer of the calendar. The earliest surviving text that lists all twenty-four terms by name is the astronomical treatise of the Huainanzi (淮南子·天文訓), compiled in the second century BCE. The Book of Rites separately records a ruler going out to the western suburb on this day to greet autumn; west is the direction assigned to metal in Five Phase correlation, so the autumn–west–metal chain was already fixed in pre-Qin thought.

In Bazi (八字 bā zì) the twenty-four terms split into twelve nodes, which open a month, and twelve mid-terms, which fall inside one. Liqiu is a node, so the month branch flips from Wei (未) to Shen (申) at the instant the sun reaches 135°. That instant is a clock time, not a calendar day. Anyone born on the day of Liqiu needs the exact minute for that year, converted to true solar time for the birth longitude; get it wrong and the whole month pillar changes, taking the direction and starting age of the luck cycles with it.

Shen hides Geng metal as its principal qi, with Ren water and Wu earth beneath, and in the twelve-stage life cycle it is where water is said to be born. It also heads the Shen–Zi–Chen water trine. So although Liqiu nominally marks the moment metal takes command, the chart quietly carries a second reading: metal generates water, and the cool of autumn and the rise of water are two points on one line. Reading a Liqiu-month chart means asking both whether the metal is too sharp and whether Ren water has surfaced in the stems.

A widely repeated folk couplet claims an “early” Liqiu brings a cool autumn while a “late” one brings a scorching tail. What counts as early or late has at least three incompatible definitions: whether the term arrives before or after noon, whether it falls in the sixth or the seventh lunar month, and whether it lands inside the dog days. In a given year these tests can point in opposite directions, which is a useful reminder that the couplet is regional folk induction, not a calendrical rule.

Hearing Liqiu as “it turns cool now” is the easiest slip. A term name records where the sun is, not what a thermometer says, and most of China stays hot for weeks afterwards. The second mistake crosses two systems. Ziwei Doushu (紫微斗數 zǐ wēi dǒu shù) sets the Life Palace from the lunar month and the birth hour and ignores the solar terms entirely, so Liqiu changes a Bazi month pillar and does nothing whatever to a Zi Wei chart. The two arts run on different calendars, and their rules do not transfer. Dashu, Liqiu and Chushu are often collapsed into one idea. They are not. Dashu marks the peak of heat, Liqiu the calendrical boundary of the season, and Chushu the point where the heat genuinely withdraws. In pillar terms the split is sharper still: Liqiu opens the Shen month, Bailu opens You, Hanlu opens Xu — three nodes, three new month pillars — while Chushu, Qiufen and Shuangjiang sit in the middle of those months and start nothing.

Liqiu's three five-day phases run: cool winds arrive, white dew descends, the cold cicada sings. In order they trace a shift in wind direction, the widening day–night temperature gap that leaves dew on leaves, and the thinning of the cicada chorus. For farmers this was a watch point and not a festival: mid-season rice was filling out and late rice going into the ground, and old agricultural manuals treat drought or flood in these weeks as decisive for the harvest.