When will you be ambushed?

Commonly known as the summer solstice, the third night will count as three volts, and the date of three volts is determined by the date of solar terms and the date of the main branch. According to the provisions of the lunar calendar, counting volts does not start from the summer solstice. The so-called "counting on the third Geng day after the summer solstice" means that the third Geng day after the summer solstice is "initial", the fourth Geng day is "intermediate" and the fifth or sixth Geng day is final. This is the so-called "three volts", and the period between two Geng days is 10 days, the first and last volts.