The Celestial Almanac / A small lesson
Where the heavens mark the days.
The Sixtyfold
Cycle.
Twelve Earthly Branches.
Only half the story.
You may have seen years named after animals. Each animal is associated with one of twelve Earthly Branches. But a full cycle pairs those branches with a second sequence: ten Heavenly Stems.
Advance both sequences together, one place at a time. Watch when the starting pair returns.
The formal name is the sexagenary cycle. “The Sixtyfold Cycle” is this lesson’s title. The cycle is also used for days and other units of time, not only years.
Two sequences / One shared step
Begin with 甲子.
One stem. One branch.
Move both by one.
The fixed line marks the current pair. Both rings turn one place per step.
Drag left to advance, right to go back. Release to snap to a pair. Use ← / → when the dial is focused. Vertical swipes scroll the page.
Pair 1 of 60
甲子
jiǎ zǐ
0steps from the start
This is the first pair. No step has been taken yet.
Stem 1 / 10 · Branch 1 / 12
“Day” is one step in this demonstration. No calendar date is assigned. Play begins at 甲子; Pause lets you resume.
10 Heavenly Stems
Repeat every 10 steps- 甲jiǎ
- 乙yǐ
- 丙bǐng
- 丁dīng
- 戊wù
- 己jǐ
- 庚gēng
- 辛xīn
- 壬rén
- 癸guǐ
12 Earthly Branches
Repeat every 12 steps- 子zǐ
- 丑chǒu
- 寅yín
- 卯mǎo
- 辰chén
- 巳sì
- 午wǔ
- 未wèi
- 申shēn
- 酉yǒu
- 戌xū
- 亥hài
The meeting point
Ten meets twelve.
At sixty.
A shared step advances both sequences. The stem returns to its start after 10 steps; the branch after 12. Both first return together after 60 steps: the least common multiple of 10 and 12.
That gives 60 distinct pairs, not every possible combination of a stem and a branch.
癸亥 guǐ hài
59 steps from the first pair.
甲子 jiǎ zǐ
Back to pair 1. The cycle begins again.
The complete sequence
Sixty different pairs.
Select a pair to visit it. The number is its position in the cycle, not the number of steps already taken.
One lesson, one boundary
This shows how the pairing works. It does not convert a birth date or a calendar date, determine someone’s cycle signs, or calculate an almanac.
Continue to Baker Street →