The 10 astronomical keys of the Chinese New Year

Chinese New Year is celebrated on January 22, 2023.

It is the beginning of the year 4721, a year under the sign of the Rabbit.

However, the beginning of the previous year, 4720, was celebrated on February 1, 2022 and the next one will be celebrated on February 10, 2024. What are these variations due to?

We reveal 10 astronomical keys to learn a little more about the enigmatic Chinese calendar.

1. Easy rule.

Chinese New Year is celebrated on the date of the second new moon after the winter solstice.

This date refers to the 120 East meridian, close to Beijing.

Let's apply the rule to this year: the solstice was on December 22, 2022, the first new moon of winter was on December 23, and the second on January 21, 2023 at 9:53 p.m.

But in Beijing it is 7 hours longer, so in the Beijing meridian the new moon takes place at 4:53 am on January 22, and that is the date that is considered the beginning of the Chinese New Year.

2. Beginning of the year.

Due to the rule above, the date of the first day of the Chinese calendar, when we refer it to our Gregorian calendar, varies from year to year, but always falls between January 21 and February 21.

3. Origin.

According to tradition, the origin of the Chinese calendar from which the years are counted is located in the year of the coronation of the legendary Yellow Emperor or Huangdi, the year 2698 BC.

C., that is why the Gregorian year 2023 corresponds to the Chinese year 4721, the sum of 2023 and 2698. (This, however, is not a unique convention, some consider that this is the year 4720.)

4. Lunations.

The Chinese calendar is primarily lunar.

The duration of its months is determined by the time necessary for a lunation, that is, the interval between two new moons, which varies between 29.27 and 29.83 days.

Since it is important that the months have an integer number of days, the Chinese calendar contains months of 29 or 30 days.

Each month begins with the new moon and, when it has 30 days, it is divided into 3 weeks of 10 days.

Chinese zodiac

5. Lunisolar.

On average, a lunation (and therefore the lunar month) lasts 29.53 days.

12 lunar months are 354.36 days.

Since the mean solar year has 365.25 days, there is a difference of 10.89 days per year.

To keep the Chinese calendar in step with the seasons (which are given by the solar year), an extra lunar month is added approximately every 3 years, thus creating a 13-month year.

The years of 12 months are called common, those of 13 months are embolismal, leap or intercalary years.

This makes the Chinese calendar lunisolar.

6. Chang's cycle.

Chinese years are grouped according to the Chang cycle, a periodicity known in the West as the Meton cycle.

It is a common approximate multiple of the orbital periods of the Earth and the Moon: it contains an integer number of solar years and an integer number of lunar years.

Its duration is 19 solar years, which is equivalent to 235 lunar months.

This period can be broken down into 12 'common' years of 12 lunar months (which can be 354 or 355 days) and 7 embolic years of 13 months (which can be 383 or 384 days).

Chinese constellations around the north pole Tang Dynasty, 8th century

7. Embolic.

Approximately every three common years, one of these embolic or leap years is inserted, duplicating, in that year, one of the 12 basic months.

The rules to determine which month should be duplicated are complex, but they take into account that the winter solstice always remains in the 11th month. The embolismal year was 2020 and it will also be in 2023, in which a second extra month will be inserted after the second normal month.

8. Jioqi.

In addition to the lunar months, the Chinese calendar is also divided into 24 solar partitions (Jioqi) that correspond to 24 sections of 15 degrees in the path of the Earth in its orbit around the Sun.

9. The life of astronomers depended on it.

Traditionally, calendars were defined in advance according to the forecasts of astronomers who responded with their lives for possible errors.

Since 1949 the calendar has been set at the Purple Mount Astronomical Observatory in Nanking.

10. Horoscope.

The years of the Chinese calendar are grouped into 60-year cycles similar to the centuries of the Gregorian calendar.

Each of these cycles results from the combination of the yin-yang pair, the five celestial elements (metal, water, wood, fire and earth) and the twelve terrestrial branches (represented by the twelve animals: rat, ox, tiger, rabbit, dragon, snake, horse, goat, monkey, rooster, dog and pig).

Although there are 120 possible combinations, only half of them are considered in strict order (the other half are not used).

All this symbology gives rise to a very refined astrology, but as in Western astrology, there is no scientific basis for all these beliefs.

2023 is a year under the sign of the Rabbit, the element of water and yin.

Rafael Bachiller

is director of the National Astronomical Observatory (National Geographic Institute) and academic of the

According to the criteria of The Trust Project

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