What's the difference between sunny and cloudy days?

Sunny days and cloudy days are the traditional yin and yang calendars in China, which are based on the yin and yang of the five elements in a year.

Sunny days refer to festivals in the solar calendar, such as New Year's Day, Spring Festival, Lantern Festival, Dragon Boat Festival, Mid-Autumn Festival and National Day, while cloudy days refer to festivals in the lunar calendar, such as the 30th of the twelfth lunar month, the first day of the first month, the 15th of the first month, the 15th of July and the 15th of August. The division between sunny and cloudy days is an algorithm of Wei Zi's bucket number, which is determined according to the yin and yang of the five elements in a year.

In addition, in the yellow calendar, every day is marked as one of "solar calendar" or "lunar calendar". If a day is marked as "solar calendar" in the yellow calendar, it means that it is a sunny day, and vice versa.

In a word, sunny days and cloudy days are divided according to China's traditional lunar calendar, which reflects the understanding and application of Yin-Yang and Five Elements in China's traditional culture.