Autumn in the Korean 24 Jieqi calendar begins on Liqiu (Ipchu) around August 7 and runs through Shuangjiang (Sanggang) around October 23. These six solar terms govern harvest, the cooling-down of the Fire excess of summer, and the Monkey-Rooster-Dog month pillars. This guide walks through each one.
Many casual writers in English describe the 24 Jieqi as a 'lunar calendar' feature, but that is incorrect. The 24 Jieqi is a solar calendar. Each Jieqi marks a 15-degree progression of the sun's apparent path through the year. Twenty-four times 15 equals 360. So the 24 Jieqi divides the solar year into 24 equal arcs.
Because it is solar, the 24 Jieqi falls on roughly the same Gregorian date every year. Lichun (the start of spring) is around February 4. Lixia (start of summer) is around May 5. The dates shift by no more than one day from year to year.
The Korean Saju calendar uses the 24 Jieqi (not the lunar calendar) to determine your month pillar. Specifically, the twelve 'odd' Jieqi (Lichun, Jingzhe, Qingming, Lixia, Mangzhong, Xiaoshu, Liqiu, Bailu, Hanlu, Lidong, Daxue, Xiaohan) mark the boundaries between month pillars.
This is why your Saju new year is not the same as Korean Lunar New Year. The Saju new year is Lichun, around February 4. If you were born between Lunar New Year and Lichun, your Saju year pillar can be the previous year even though your lunar birthday looks like the new year. This is one of the most common sources of error in free online Saju calculators.
Korean Saju assigns each three-month season a dominant element. Spring (Tiger-Rabbit-Dragon months) is Wood. Summer (Snake-Horse-Sheep months) is Fire. Autumn (Monkey-Rooster-Dog months) is Metal. Winter (Pig-Rat-Ox months) is Water. The transition months between seasons (Dragon, Sheep, Dog, Ox) all carry Earth.
This seasonal element assignment is the foundation for the 'strength of the Day Master' calculation. A Day Master born in its own peak season is structurally strong. A Day Master born in a controlling-element season is structurally weak. Day Master strength then drives nearly every subsequent reading.
Modern Korea still uses the 24 Jieqi calendar in agriculture, traditional medicine, and Saju. Korean weather forecasters reference Jieqi terms (Cheoseo for the end of summer heat, Daehan for the deepest winter cold). Traditional Korean medicine prescribes dietary changes by Jieqi. And Saju practitioners use it daily as the foundation of their calendar work.
If you want to understand Korean traditional thinking at any depth, learning the 24 Jieqi is one of the highest-leverage moves you can make. It is the operating system underneath a thousand other Korean cultural conventions.
Korean Saju and Western astrology answer different questions, so direct accuracy comparison is misleading. For career, money, and timing questions, Korean Saju produces more concrete, decision-useful predictions because the Sip-sin system directly labels which characters represent those themes. For emotional and psychological questions, Western astrology has a richer symbolic vocabulary. Most Korean practitioners use both, treating them as complementary.
The two-hour window of your birth determines your Hour Pillar, which represents your children, your late-life destiny, and your hidden talents. A chart without the hour is three quarters complete. If you do not know your hour, you can still get a meaningful reading from the other three pillars, but the most personal layer is missing. Korean birth certificates traditionally record the hour, which is why most Koreans know it.
Your eight characters are fixed for life. What changes is the 10-year Daewoon (Great Luck) overlay and the annual year pillar. So at any given moment your "reading" is the static eight characters plus the current Daewoon plus the current year. As you move through life, the Daewoon shifts every ten years and the year pillar shifts every solar new year (around February 4), producing a constantly updating prediction even though the underlying chart never changes.
Korean Saju is not a falsifiable scientific theory in the Popper sense; it is a 1,400-year-old interpretive tradition. What is empirically defensible is that Korean Saju is internally consistent (the rules are deterministic), culturally stable (the same reading is reproducible across practitioners), and decision-useful (real Korean institutions use it for real decisions). Whether the underlying causal claim is correct is a separate question that Korean Saju, like astrology in any tradition, cannot definitively prove.