Heavenly Stems and Earthly Branches: The Complete Guide to China's 60-Year Calendar Cycle

The Heavenly Stems and Earthly Branches (天干地支, Tiāngān Dìzhī) form one of the oldest and most influential systems in traditional Chinese culture. Together, they create the Sexagenary Cycle, a repeating 60-year cycle that has been used for more than two thousand years to identify years, months, days, and even hours.

This system lies at the heart of the Chinese Calendar, the Chinese Zodiac, the Five Elements, and many traditional cultural practices. It has influenced astronomy, history, literature, philosophy, and Chinese astrology throughout the centuries.

Today, although the Gregorian calendar is used for everyday life, the Heavenly Stems and Earthly Branches remain an important part of Chinese cultural heritage and continue to be studied by historians, scholars, and people interested in traditional Chinese culture.

Quick Answer

The Heavenly Stems and Earthly Branches are two traditional Chinese cyclical systems.

• 10 Heavenly Stems
• 12 Earthly Branches

When combined in sequence, they create a 60-year repeating cycle, also known as the Sexagenary Cycle.

This system is used in:

• Chinese Calendar
• Chinese Zodiac
• Five Elements
• Historical records
• Traditional Chinese astrology

What Are the Heavenly Stems?

The Heavenly Stems (天干, Tiāngān) are a sequence of ten symbols.

They are:

Each Heavenly Stem is associated with:

• Yin or Yang
• One of the Five Elements

Heavenly Stems and the Five Elements

The Ten Heavenly Stems are divided into Yin and Yang forms of the Five Elements.

This relationship connects the calendar directly with traditional Chinese philosophy.

👉 Read more:

Five Elements

What Are the Earthly Branches?

The Earthly Branches (地支, Dìzhī) are a sequence of twelve symbols.

These twelve branches later became closely associated with the Chinese Zodiac.

👉 Read more:

Chinese Zodiac

How the 60-Year Cycle Works

The Heavenly Stems repeat every 10 years.

The Earthly Branches repeat every 12 years.

Because 10 and 12 share the least common multiple of 60, the two systems repeat together every 60 years.

For example:

After the 60th combination, the cycle begins again with Jia-Zi (甲子).

This repeating sequence is known as the Sexagenary Cycle.

The Meaning of Jia-Zi (甲子)

The combination Jia-Zi (甲子) marks the beginning of every 60-year cycle.

It combines:

• Jia (Yang Wood)
• Zi (Rat)

Because it is the first possible pairing, Jia-Zi has traditionally symbolized:

• A new beginning
• Renewal
• The start of a complete cycle

Many historical documents refer to years by their Jia-Zi cycle names.

Heavenly Stems, Earthly Branches, and the Chinese Zodiac

Each Chinese Zodiac year combines:

• One Heavenly Stem
• One Earthly Branch

For example:

This explains why the Chinese Zodiac is actually a 60-year cycle, rather than simply repeating every 12 years.

Historical Uses

For centuries, the Heavenly Stems and Earthly Branches were used to record:

• Years
• Months
• Days
• Traditional time periods
• Historical events
• Imperial documents

Many ancient Chinese texts identify dates using the Sexagenary Cycle rather than Gregorian years.

Heavenly Stems and Traditional Timekeeping

Historically, the Earthly Branches were also used to divide the day into twelve double-hours, with each period lasting approximately two modern hours.

For example:

This traditional system was widely used before modern clocks became common.

Heavenly Stems and Earthly Branches Today

Although the Gregorian calendar is now the standard for everyday life, the system continues to appear in:

• Chinese cultural education
• Traditional calendars
• Historical research
• Museum exhibitions
• Chinese astrology
• Lunar New Year publications

It remains one of the most recognizable components of traditional Chinese chronology.

Frequently Asked Questions

What are the Heavenly Stems?

The Heavenly Stems are a sequence of ten traditional symbols used in the Chinese calendar. Each stem is associated with Yin or Yang and one of the Five Elements.

What are the Earthly Branches?

The Earthly Branches are twelve traditional symbols that correspond to the twelve Chinese Zodiac animals and form part of the traditional Chinese calendar system.

Why is the cycle 60 years?

The Heavenly Stems repeat every 10 positions, while the Earthly Branches repeat every 12 positions. Their combinations repeat after 60 unique pairings.

Are the Earthly Branches the same as the Chinese Zodiac?

The Earthly Branches are the traditional symbols behind the zodiac cycle. Each branch corresponds to one zodiac animal, such as Rat, Ox, Tiger, or Rabbit.

Is the Sexagenary Cycle still used today?

It is no longer used for everyday civil dating, but it remains important in traditional Chinese culture, historical studies, calendars, and discussions of the Chinese Zodiac.

Related Guides

• Chinese Calendar
• Chinese Lunar Calendar
• Chinese Zodiac
• Five Elements
• Yin and Yang
• Chinese New Year
• 24 Solar Terms
• Chinese Zodiac Compatibility
• Chinese Zodiac Calculator