Sixty Jiazi: The Sexagenary Cycle and How It Works

A Chinese calendar may describe a year with two characters rather than a number. Those characters identify a position in a cycle, not a unique date. To read them correctly, you need to know how the two lists combine and which unit of time they are counting.

The table below gives all 60 names in order and one modern run of year labels. The explanation also separates the calendar’s counting mechanism from later animal, element and fortune-telling interpretations.

Two Ordered Lists Advance Together

The Heavenly Stems (天干, tiāngān) are the ordered series of ten labels used as the first part of a cycle pair. The Earthly Branches (地支, dìzhī) are the ordered series of twelve labels used as the second part of a cycle pair. Gan-Zhi (干支, gānzhī) is the combined stem-and-branch system.^[1]

The stem order is 甲、乙、丙、丁、戊、己、庚、辛、壬、癸. The branch order is 子、丑、寅、卯、辰、巳、午、未、申、酉、戌、亥. The complete table supplies the readings of their combinations; the dedicated ten stems и twelve branches guides explain the individual labels.

Start at the first item in each list. At the next position, move both forward once. When the ten-label list finishes, return it to its beginning while the twelve-label list keeps advancing. Neither list waits for the other, and you do not choose labels independently.

That last point is the key distinction. The system is a synchronized sequence, not a menu of every possible combination. To reproduce it, keep two counters moving at the same rate.

Why the Cycle Has 60 Names

Ten and twelve have a least common multiple of 60. After ten steps, the stems have returned to their starting point, but the branches have not. After twelve steps, the branches have returned, but the stems have moved two positions beyond their start. Sixty is the first positive number of steps that returns both together.

This gives six complete rounds of the stems and five complete rounds of the branches. Multiplying 10 by 12 would produce 120 possible combinations only if the two lists could be paired freely. That is not how this sequence works.

In later correlative classifications, the labels alternate Yang (阳, yáng) and Yin (阴, yīn). Odd positions pair with odd positions and even positions with even positions, so the sequence produces same-polarity pairings. The synchronized counting rule explains the available pairs; the polarity labels describe their traditional classification.^[5]

A useful way to check the pattern is to compare positions 1,11 and 13. At 11, the stem list has restarted while the branch list is near its end. At 13, the branch list has restarted while the stem list has reached its third item. Only after the final position do both return together.

The Complete Sixty Jiazi Table

The paired names below follow the standard sequence. Each year shown is the Gregorian year in which the corresponding Chinese calendar year begins, not a claim that the pair covers January 1 through December 31. The modern reference run begins in 1984; adding or subtracting 60 gives another occurrence of the same annual label.^[1][2]

At position 60, the next step returns to position 1. The table can also name days or other units, but its year column must not be reused as a day-count formula. A calendar’s day designation requires its own continuous count and a verified reference date.

Find a Year without Losing the Boundary

For a modern calendar-year lookup, first identify the convention being used. The official calendar practice described for Hong Kong changes the annual designation on the first day of the first Chinese calendar month, commonly called Lunar New Year’s Day. Some fortune-telling systems instead use Start of Spring (立春, lìchūn), a solar term. Those boundaries can fall on different dates.^[3]

For a birth in January or February, check the actual date before assigning the calendar year. The Chinese and Gregorian calendar comparison explains why their year boundaries differ.

For the ordinary Chinese-calendar convention, the first year in the reference run began on February 2, 1984.^[2] Use this procedure once you have established the correct year start:

1. Identify the year start: Determine which Chinese calendar year contains the date, using the stated boundary convention.
2. Count from 1984: Subtract 1984 from the Gregorian year in which that Chinese calendar year begins.
3. Reduce to a cycle position: Divide the difference by 60, keep a nonnegative remainder and add 1.
4. Read the pair: Find that numbered position in the sixty-pair table.

For example,2026 minus 1984 is 42, so the year beginning in 2026 occupies position 43. For a year earlier than 1984, keep the remainder between 0 and 59:1983 gives a remainder of 59 and therefore position 60. These are year-label calculations, not substitutes for checking an early-year birthday.

Start of Spring belongs to the 24 solar terms. It is not another name for Lunar New Year, and its use in one interpretive system should not silently change the convention used by a public calendar.

From Shang Day Counts to Later Calendar Uses

The cycle’s early evidence concerns days. In late Shang oracle-bone inscriptions, around 1200 BCE, the paired signs already functioned as an ordered counting system and dated divination ceremonies. This is a documented use, rather than proof of a precise prehistoric invention date.^[4]

Animal and element correlations belong to later interpretive developments. They should not be projected backward as the proven original meanings of every sign in the earliest inscriptions. The old counting labels and the explanations subsequently attached to them are related subjects with different evidence.^[4]

The sequence was later used for years, months, days and divisions of a day. A sixty-day count advances daily; it does not restart whenever a new year begins. Month and hour designations also require the rules appropriate to those units.^[2]

For Chinese historical dating, an inscription’s reign, era or surrounding record may be needed to locate a repeated label in absolute chronology.

More Than a Zodiac Animal

The Chinese zodiac (生肖, shēngxiào) associates the twelve branches with animals. It supplies one part of the annual designation, not the whole sixty-position sequence. Two years twelve years apart can share an animal while having different stems.^[2]

Wuxing (五行, wǔxíng), often translated as the Five Phases or Five Elements, provides another later layer of correlations involving wood, fire, earth, metal and water. These are traditional classifications, rather than scientific materials from which a person’s character is composed.^[4]

Keep the task in view. A cycle table can identify a label accurately without establishing a personality or predicting a life event. The distinction between a birth-year animal and a fuller chart is explained in BaZi versus the Chinese zodiac.

A return of the same year pair also helps explain the cultural importance of the sixtieth birthday. The calendar has completed one full round of annual labels; the occasion’s family customs are a further cultural subject, not a property of the arithmetic itself.

FAQs About the Sixty Jiazi Cycle

Why are there 60 pairs instead of 120?

Both lists advance together. Their first shared return occurs after 60 steps, so only half the combinations obtainable by freely mixing ten and twelve labels appear in this sequence.

Does the same pair return every 12 years?

The branch returns after twelve annual steps, but the stem generally differs. Both parts of the annual name return together after sixty years.

Does the cycle begin on January 1?

An annual designation does not ordinarily change on January 1. Check whether the source uses the Chinese calendar year beginning at Lunar New Year or an interpretive convention tied to Start of Spring.

Does one pair identify a unique historical date?

No. The names repeat, and the same sequence can count different time units. To identify a historical date, you also need enough surrounding chronological information to determine which occurrence and which unit are intended.

Источники

[1] Hong Kong Observatory. Heavenly Stems and Earthly Branches (Небесные стволы и Земные ветви)

[2] E. G. Richards, hosted by the US Naval Observatory. Calendars, in the Explanatory Supplement to the Astronomical Almanac

[3] Hong Kong Observatory (Гонконгская обсерватория). What year is it today? (какой сейчас год?)

[4] William G. Boltz, Max Planck Research Library. The Chinese Sexagenary Cycle and the Origin of the Chinese Writing System

[5] Wan Minying, classical text transcription on Wikisource. Sanming Tonghui, Volume 2: stem and branch classifications