Is leap February mid-spring

Mid-spring, called mid-spring February in ancient times, is the second month of the lunar calendar. Midspring was originally determined according to the solar terms of a year, but since the Han Dynasty, it has been set between the first day of the first month and the fifteenth day of the first month. Midspring, also known as "Yue Ling" in ancient times, can also be called "Yue Ling" because it is calculated according to solar terms and seasons.

Leap February, also called Yue Ling in ancient times, is the 13th month of the lunar calendar. Leap February is determined according to the annual solar terms, between the last day of February and the fifteenth day of March.

Leap February did not exist originally, but because February every year is not equal to the solar terms of one year, one month was added to adjust the gap between the solar terms and the lunar calendar. Therefore, leap February is also called "Yue Ling".

The frequency of leap February is second only to leap March, and the frequency of leap February is moderate around 2 1 century, generally once every 19 years (such as 2004 and 2023).

Since then, the frequency of leap February has gradually decreased, becoming a rare leap month. Every century in the 25th-28th century has a leap February, but there is no leap February in the 29th-30th century, the 36th-38th century and the 40th-44th century. Spring Festival and Dragon Head Festival are the earliest, and the latest year of Shangsi Festival is usually in February.

There are two calendars in most parts of China: one is the solar calendar, and the other is the lunar calendar (also called the summer calendar). The solar calendar, also called the solar calendar, is based on the tropical year. Because the length of the tropic year is equal to 365.2422 average solar days (that is, 365 days, 5 hours, 48 minutes and 46 seconds), it is not a whole day.

So the solar calendar takes 365 days as the average year, that is, the "average year". In order to clear the gap between it and the actual tropic year, the Gregorian calendar adds 97 days in 400 years, or adds one day in February every four years. This is a leap year of the solar calendar, and it is also the "leap February" of the solar calendar.