A calendar is a system of arranging days according to astronomical events for regulating everyday life. The calendar is divided into three types: the lunar calendar, the solar calendar and the lunisolar(lunar-solar) calendar. The current international Gregorian calendar belongs to the solar calendar. Solar calendars (Yang Calendar) are based on the positions of the sun through the seasons.
Chinese Lunar Calendar
How do you know today’s lunar date without using a mobile, computer or internet? We know that The lunar calendar is based on the moon phase cycle. Therefore the lunar date of the day can be inferred from the shape of the moon. Of course, under the influence of some factors such as the size of the moon, the brightness of the light, and the subjective judgment of people, this method of speculation may have an error of 1-2 days.
The traditional Chinese calendar is known as the Lunar Calendar, and Yin Calendar, which is based on the moon’s orbit around the Earth. The first day of a month is the day when an astronomical new moon occurs. The Islamic calendar is a kind of lunar calendar. The moon phases in order are shown below:
- New Moon.
- Waxing Crescent Moon.
- First Quarter Moon.
- Waxing Gibbous Moon.
- Full Moon.
- Waning Gibbous Moon.
- Third Quarter Moon.
- Waning Crescent Moon.
Moon phase image of a lunar month
Chinese Nong Li Calendar
“Nong li” and “yin Li”, these two names can be considered equivalent by many people. But in astronomy, “Nong li” and “yin Li” are two completely different concepts. “Nong Li” is a type of “Lunar-solar Calendar”, and “Yin Li” refers to the “Pure Lunar Calendar”.The modern Chinese calendar is a combined solar/lunar calendar, which is called a lunisolar calendar. The Chinese Calendar integrates the movement of the moon as well as that of the sun. It’s used to determine the dates of traditional Chinese festivals, like the Chinese lunar new Year and Mid-Autumn, and also used for Chinese zodiac astrology. Most Chinese still celebrate traditional festivals based on the lunar calendar nowadays.
Leap Month and Leap Year
Since each lunation are approximately 29.5306 days, and a lunar year is 10.875 days shorter than the solar year, an extra month needs to be added to the usual 12 months. Every 19 years is about 209 days shorter, that is, 7 months. Therefore, it’s necessary to add periodic days if a lunar-year calendar is to be kept in step with the solar year. 7 leap years are set in every 19 years and every leap year has 13 months.
Approximately every three years, a leap month is added to the Chinese calendar. The leap month added after a certain month is called “a leap month”. Count the number of new moons between the 11th month in one year and the 11th month in the following year. A leap month is inserted if there are 13 New Moons from the start of the 11th month in the first year to the start of the 11th month in the next year.
A leap year has one more day than a normal year. February in a normal year has 28 days, while February in a leap year has 29 days. In the third year of the lunar calendar, there is one leap month, in the fifth year, there are two leap months, and in the nineteenth year, there are seven leap months.
What is the Chinese Calendar like?
Chinese calendar uses regular two characters.
Days 1 to 10 of a month are written with the characters 初 (Chu, which means ‘beginning’ or ‘first’). For example, the 3rd of the month is 初三( Chu San).
Days 11 to 20 are written as regular two-character, with the character 十(Shi, which means ‘10’). For example, 十二 (Shi Er) is the 12th day of the month.
Days 21 to 29 are written with the character 廿 (Er, which means ‘20’). For example, 廿一 (Er Shi Yi) is the 21st day of the month.
The first day of a lunar month is called “Chu Yi” in Chinese. When the moon is full, it comes to the middle of the month, which is called “Shi Wu”.
Moon phase images from the first to the fifteenth day of the lunar month
The correspondence between the Date in the Chinese calendar and the solar calendar is shown in the table below.
Chinese calendar and the solar calendar
| 1 | 初一 (Chu Yi) | the 1st day of a month | 2 | 初二 (Chu Er) | the 2nd day of a month |
| 3 | 初三 (Chu San) | the 3rd day of a month | 4 | 初四 (Chu Si) | the 4th day of a month |
| 5 | 初五 (Chu Wu) | the 5th day of a month | 6 | 初六 (Chu Liu) | the 6th day of a month |
| 7 | 初七 (Chu Qi) | the 7th day of a month | 8 | 初八 (Chu Ba) | the 8th day of a month |
| 9 | 初九 (Chu Jiu) | the 9th day of a month | 10 | 初十 (Chu Shi) | the 10th day of a month |
| 11 | 十一 (Shi Yi) | the 11th day of a month | 12 | 十二 (Shi Er) | the 12th day of a month |
| 13 | 十三 (Shi San) | the 13th day of a month | 14 | 十四 (Shi Si) | the 14th day of a month |
| 15 | 十五 (Shi Wu) | the 15th day of a month | 16 | 十六 (Shi Liu) | the 16th day of a month |
| 17 | 十七 (Shi Qi) | the 17th day of a month | 18 | 十八 (Shi Ba) | the 18th day of a month |
| 19 | 十九 (Shi Jiu) | the 19th day of a month | 20 | 二十 (Er Shi) | the 20th day of a month |
| 21 | 廿一 (Er Shi Yi) | the 21st day of a month | 22 | 廿二 (Er Shi Er) | the 22nd day of a month |
| 23 | 廿三 (Er Shi San) | the 23rd day of a month | 24 | 廿四 (Er Shi Si) | the 24th day of a month |
| 25 | 廿五 (Er Shi Wu) | the 25th day of a month | 26 | 廿六 (Er Shi Liu) | the 26th day of a month |
| 27 | 廿七 (Er Shi Qi) | the 27th day of a month | 28 | 廿八 (Er Shi Ba) | the 28th day of a month |
| 29 | 廿九 (Er Shi Jiu) | the 29th day of a month | 30 | 三十 (San Shi) | the 30th day of a month |
| 31 | 三十一 (San Shi Yi) | the 31st day of a month |
The gregorian calendar is a solar calendar, while the Chinese calendar is a lunar calendar.
Converter
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