Questions about the lunar calendar and the national calendar

The lunar calendar and the national calendar are two different ways of calculating time. The lunar calendar, also called the lunar calendar, is a traditional Chinese calendar based on the cycle of the moon, with the new moon on the first day of each month and the full moon on the 15th of each month. There are twelve months in a lunar year, and the length of each month is not fixed, usually 29 days, 30 days or 29 and a half days. The lunar calendar is still widely used in daily life in China, and is also highly valued during important moments such as the Spring Festival and Dragon Boat Festival in certain traditional festivals. The national calendar, also called the solar calendar or the Gregorian calendar, is a calendar based on the revolution of the sun and 365 days in a year. Therefore, the length of each month is relatively fixed, usually 28, 30 or 31 days. The national calendar is widely used and enjoys widespread use in other countries, such as in Western countries. The two calendars differ in calculating time, with the most obvious difference being the handling of leap years. Leap years in the lunar calendar are achieved by adding months to certain years, while in the national calendar they are achieved by adding days to every four years. Therefore, differences between the two calendars are inevitable.