What is the solar term in July 16?

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".