Today is the double Chinese Valentine's Day once every 38 years, but I checked, 76 years ago, 1930 was not a leap July, why?

Lunar leap month does not cycle every 38 years, so 1930 is not.

Determination of lunar leap month;

In the China lunar calendar, a year with a leap month is called a leap year. The general year is 12 months, 354 or 355 days, and the leap year is 13 months, 383 or 384 days. As a kind of lunar calendar, the number of days in each month depends on the monthly loss, and the time of one year is based on 12 months. In order to close the earth's cycle around the sun, that is, the tropic year, one month is added every two to four years, and the added month is a leap month, so the leap year of the lunar calendar is 13 months.

There is no thirteenth month in the lunar calendar. According to the calendar rules, leap months are repeated from February to the same month after 10, and the repeated months are leap months. For example, the leap month after April is called leap April.

Calculation of leap month in lunar leap year, three-year leap, five-year leap, 19 leap; The lunar calendar basically takes 19 as a cycle, corresponding to the same time in the Gregorian calendar. For example, in the Gregorian calendar, May 27th, 2006, 5438+0, May 27th 1982 and May 27th 1963 are the fifth day of leap April.

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