Quick Answer: What Are the Seventy-Two Pentads?
The seventy-two pentads (七十二候, qīshí’èr hòu) divide the Chinese seasonal year into three short periods for each of its 24 solar terms. A pentad (候, hòu) lasts roughly five days and has a traditional sign (候应, hòuyìng), such as a thaw, the opening of flowers or a change in bird activity. [1][2][3]
- How to count them: Three pentads per term, across 24 terms, make 72. [1][2]
- Where to start: A pentad takes its place from its solar term and its order within that term. [1][4]
- How to read the signs: They record historical seasonal knowledge and imagery, with variation by region and year. [1][3]
A pentad’s place in a list is a calendar convention. Its sign may occur earlier or later in the field.
The received Monthly Ordinances commentary begins its spring sequence with thawing ice, dormant creatures stirring and fish moving toward the ice. Three images fit inside one solar term. Together they give the turn of the season more detail than a date alone can convey. [2][5]
Three Pentads Inside Each Solar Term
The 24 solar terms are spaced at 15-degree steps in the Sun’s apparent longitude. In the traditional pentad scheme, each term contains a first, second and third period. Multiplying three by 24 gives 72. Because 72 times five is only 360 days, five days describes the approximate scale of a pentad over a full solar year. [1][2][4]
Start with the year and the local date of the parent term. The Hong Kong Observatory’s 2027 calendar, for example, places Start of Spring on February 4. In a traditional list, its first sign belongs near that opening, with the next two signs following in order before Rain Water. Rain Water starts on February 19 that year, so the three traditional signs belong in sequence between the two term openings. That gives a seasonal window even when the almanac does not print separate dates for each sign. [4][5][6]
What the Seasonal Signs Describe
A traditional sign may refer to plants, animals or a change in the weather. These examples follow the received Monthly Ordinances commentary, traditionally attributed to Wu Cheng. [2][5]
| Jieqi | First sign | Second sign | Third sign |
|---|---|---|---|
| Awal Musim Semi | East winds bring thawing | Dormant creatures begin to stir | Fish move up toward the ice |
| Air Hujan | Otters lay out fish as if in offering | Wild geese head north | Plants begin to sprout |
| Grain Full | Bitter greens come into season | Delicate grasses die back | Wheat reaches its season of maturity |
A thaw and the movement of wild geese describe changes people could observe. The image of an otter making an offering interprets animal behavior in human terms. Some signs go further into older cosmology, including a Qingming image of a field mouse changing into a bird. [2][5]
Why the Signs Can Differ by Text and Place
A study published by China’s intangible heritage museum compares a received passage of the Lost Book of Zhou with later accounts. The earlier passage places the opening of tong flowers under Grain Rain. Later sources put that sign under Qingming. The transmitted lists therefore differ even on which term opens with the same blossom. [5][7]
The system grew from using signs such as flowering, migration and thawing to reckon seasonal change and agricultural time. A plant may flower earlier in a warm year or later at a cooler location. The traditional names preserve a seasonal sequence, while actual field records describe what happens in a given place and year. [1][2][3]
FAQs About the Seventy-Two Pentads
Are the pentads lunar months?
A pentad is one of three short periods associated with a solar term. A lunar month begins on the date of a new moon and has 29 or 30 days. [1][4][8]
Do all historical lists have the same signs?
Lists can differ. The opening of tong flowers appears under Grain Rain in one received passage and under Qingming in later accounts. [5][7]
Sumber
[1] Museum Digital Warisan Budaya Takbenda Tiongkok. The 24 Solar Terms, Customs and Stories
[2] China Intangible Cultural Heritage Digital Museum. Imperial Poems on the Seventy-Two Pentads
[3] Chinese Journal of Agrometeorology. Historical Changes, Characteristics and Scientific Interpretation of the Seventy-Two Pentads
[4] Hong Kong Observatory. The 24 Solar Terms
[5] Wikisource. Collected Explanations of the Seventy-Two Pentads of the Monthly Ordinances
[6] Hong Kong Observatory. 2027 Gregorian–Lunar Calendar Conversion Table
[7] China Intangible Cultural Heritage Digital Museum. Weather and Phenology at Qingming
[8] Standardization Administration of China. GB/T 33661-2017, Calculation and Promulgation of the Chinese Calendar