What is the accommodation? When did this festival begin?

Autumn is not a holiday, but it just means that when you enter the dog days, the temperature begins to rise and the air begins to get wet.

Entering volts means entering "three volts". There is a folk proverb, "The first night falls in summer", which is the basis for establishing the first autumn. The almanac stipulates that "the number of volts starts from the third day of summer", that is to say, "it starts to count down from summer" and begins to fall on the third "Geng Day". The "Geng Day" here refers to the days prefixed with "Geng" in the ancient "Ganzhi Jiri Law".

The so-called "heat is in three volts" can be divided into initial, middle and final three volts, and its date is determined by the date of the solar terms. The climate in dog days is characterized by "high temperature and high humidity", because the southeast wind blows in dog days and the air is humid. In dog days, humidity and temperature are high.