Why is there no 65438+February 30th (lunar calendar) this year?

Why is there no New Year's Eve dinner this Spring Festival?

Xinhua News Agency, Nanjing, 65438+ 10/5 (Reporter Cai, Zhou Runjian) The Spring Festival is approaching, and it is not difficult for people from all over the country to find that this year will be the first day of the Lunar New Year, and there will be no 30 years. Why is there such a calendar phenomenon

Wang Sichao, a researcher at Purple Mountain Observatory, Chinese Academy of Sciences, revealed that the moons in the lunar calendar in China are arranged according to the cycle of the moon's profit and loss, which is called "Shuowangyue". The average length of a lunar month is 29 days 12 hours and 44 minutes (29.5306 days), which is not an integer. The number of days in a month should be expressed as an integer, so sometimes it is a small month with 29 days. Sometimes it's a big month, 30 days.

Then how can you be sure how many days there are in a month? Astronomers regularly arrange the first day of the lunar month on the day when the "new moon" is located. The "new moon" is the moment when the moon is between the sun and the earth, that is, when the yellow meridian of the moon and the yellow meridian of the sun are the same (people on the earth can't see the moon at this time), so the number of days between the two new moons is determined. The first day of the twelfth month of the Year of the Rooster coincides with the first day of the first month of the Year of the Dog, so there is no 30th anniversary.

As we know, the moon revolves around the earth, and the earth revolves around the sun with the moon, resulting in the cycle of "new moon" and "looking" of the moon and the changes of the moon. Therefore, fundamentally speaking, the new moon is a natural phenomenon caused by the relative movement between the moon, the earth and the sun.

Wang Sichao said that such a change in the lunar calendar made the public in China enter the Year of the Dog one day earlier and met the most loyal friend of mankind, the Golden Dog. The golden dog not only symbolizes the harmonious coexistence between human beings and nature, but also is brave and full of vitality, symbolizing that the new year will be better.

According to astronomical experts, the last Spring Festival without 30th anniversary appeared in 2003, but the next Spring Festival will appear again in 20 12.