【Popular science】Rare! This year's Lantern Festival is very "naughty", "fifteen moons and seventeen rounds"

On February 15, the Lantern Festival will usher in the Year of the Tiger. Surprisingly, the Lantern Moon of the Year of the Tiger is not "fifteen circles" or "sixteen circles", but "seventeen circles", and the roundest moment will appear at 0:56 on February 17.

Statistics found that the most frequent occurrence of "full moon" is the sixteenth lunar calendar, followed by the fifteenth lunar calendar, the third is the seventeenth lunar calendar, and the least is the fourteenth lunar calendar.

"'Fifteen moons and seventeen circles' like this year's Lantern Festival are relatively rare. The last time it appeared was on February 26, 2013 (the seventeenth day of the first lunar month), and the next time it will reappear on March 1, 2029 (the seventeenth day of the first lunar month). But no matter when it is round, the moon that people can see with the naked eye is basically no difference, it is the same flower good full moon, which will not affect people's appreciation of the moon on the night of the Lantern Festival. Lin Yuan, a member of the Chinese Astronomical Society and an expert in tianjin astronomical science, said.

When is the best night of the Lantern Festival? According to experts, two hours after sunset is a good time to admire the moon.

In addition, some members of the public found that the Lantern Festival is very "naughty", last year's corresponding Gregorian calendar date is February 26, this year's corresponding Gregorian calendar date is February 15, and next year's corresponding Gregorian calendar date is February 5. This means that this year's Lantern Festival is 11 days earlier than last year, and next year's Lantern Festival is 10 days earlier than this year.

It is also the Lantern Festival, why is the Gregorian date early and late? Zhao Zhiheng, a member of the Chinese Astronomical Society and an expert on astronomy science in Tianjin, explained that the calendar used in ancient times on the mainland is called the lunar calendar, which is a luni-solar calendar, based on the absence of the moon, that is, the cycle of the lunar phase and the annual apparent movement of the sun. The Chinese lunar calendar stipulates that the 30 days of the big month and the 29 days of the small month, with a total of 12 synodic months, is 354 days or 355 days; in the Gregorian calendar, the earth's rotation around the sun is a return year, the common year is 365 days, and the leap year is 366 days. The difference between the two is about 11 days. In order to make up for the difference in the number of days from the year of regression, so as not to cause a serious disconnect between the month and the season, the method of adjustment is to arrange 13 months in some years, and there are two identical months, called "leaps". The rule of "leaping" is based on the twenty-four solar terms.

Due to the ingenious arrangement of "setting leaps" in the continental calendar, the Gregorian calendar date corresponding to the Lantern Festival every year is always either about 11 days in advance or postponed by about 19 days.

(Source: Cangzhou Evening News)