china edition


Chinese Calendar

Leap and Counting Years - Animal Zodiac

New Year is the most important holiday of the year for more than one quarter of the world's population. Although China uses the Gregorian calendar for public use, a special Chinese calendar is used for determing festivals.

The beginnings of the Chinese calendar can be traced back to the 14th century BCE. A legend tells us that Emperor Huangdi invented the calendar in 2,637 BCE.

The Chinese calendar is based on exact astronomical observations of the longitude of the sun and the phases of the moon. This means that principles of modern science have had an impact on the Chinese calendar.

The Chinese calendar is a combined solar/lunar calendar in that it strives to have its years coincide with the tropical year and its months coincide with the synodic months.

When determining what a Chinese year looks like, you need to make a number of astronomical calculations:

• First, determine the dates for the new moons. Here, a new moon is the completely "black" moon (that is, when the moon is in conjunction with the sun), not the first visible crescent used in the Islamic and Hebrew calendars. The date of a new moon is the first day of a new month.

• Secondly, determine the dates when the sun's longitude is a multiple of 30 degrees. (The sun's longitude is 0 at Vernal Equinox, 90 at Summer Solstice, 180 at Autumnal Equinox, and 270 at Winter Solstice).

These dates are called the "Principal Terms" and are used to determine the number of each month:

• Principal Term 1 occurs when the sun's longitude is 330 degrees

• Principal Term 2 occurs when the sun's longitude is 0 degrees

• Principal Term 3 occurs when the sun's longitude is 30 degrees


• Principal Term 11 occurs when the sun's longitude is 270 degrees

• Principal Term 12 occurs when the sun's longitude is 300 degrees

Each month carries the number of the Principal Term that occurs in that month.

In rare cases, a month may contain 2 Principal Terms; in this case the month's numbers may have to be shifted. Principal Term 11 (Winter Solstice) must always fall in the 11th month.

All the astronomical calculations are carried out for the meridian 120 degrees east of Greenwich. This roughly corresponds to the east coast of China.

Some variations in these rules are seen in various Chinese communities.