When is the double spring leap month in 2020? Leap year leap month algorithm.

When is the double spring leap month in 2020?

"Double Spring" refers to two beginning of spring:

(1) The first beginning of spring in 2020:

The eleventh day of the first lunar month in 2020 and the fourth day of the Gregorian calendar in 2020.

(2) The second beginning of spring in 2020:

December 22nd, 2020, February 3rd, Gregorian calendar 202 1 year.

Leap month in 2020: leap April (lunar calendar)

Chinese name leap April mbth leap April

Lunar day 383 -385 days lunar month 13 months.

Spring Festival date is 65438+1October 23rd-26th.

New Year's Eve, February 9-February 13.

In 2020, the festival time of double spring leap month year:

(1) Spring Festival 2020065438+1October 25th (2) Lantern Festival on February 8th, 2020.

(3) The dragon looked up on February 24, 2020 (4) Tomb-Sweeping Day on April 4, 2020.

(5) Dragon Boat Festival on June 25th, 2020 (6) Qixi Festival on August 25th, 2020.

(7) Mid-Autumn Festival September 2, 2020 (8) Mid-Autumn Festival June 2020 65438+1October 0 1

(9) Double Ninth Festival 2020 101October 25th (10) Cold Clothes Festival 202011October.

(1 1) Xiayuan Festival 2020165438+1October 29th (12) Laba Festival 202 1 065438+ 10.

(13) off-year 202 1 February 04 (14) off-year 202 1 February 1.

Explanation of leap year leap month algorithm!

Leap year: A multiple of 4 is a leap year, but a multiple of 100 is not a leap year unless it is also a multiple of 400.

A. The average period of the earth's revolution around the sun is 3,652,422 days, so it will add about 0.9688 days every four years. In order to make the calendar conform to the astronomical phenomena, there are the following provisions.

B when the number of the current year is a multiple of four, one day is added in February, which is called leap year.

C. But using this method, it will increase by about 0.03 days every 4 years, so it needs to deduct 3 days every 400 years;

(1) When the current year is a multiple of 100, it must be a multiple of 400 to be a leap year, otherwise it is a normal year.

(2) Like 1700, 1800 and 1900, all are normal years, and 2000 is a leap year.

Leap month: only in the lunar calendar, once every three years, at least according to the wheel, 19 7 leap, 2020 lunar leap in April.

A. Twelve lunar months have only about 354 days, while a tropical year has 3652422 days, with a difference of about 1 1 day.

B In order to coordinate the four seasons of the lunar calendar with the actual climate, a leap month is added about every three years. To be precise, 19 has seven leap months.