What do you mean, three days?

March 9 is the coldest day in a year, which refers to the third "nine days" from the winter solstice, that is, the winter solstice after 19-27 days. Dog days are the hottest season in a year, usually from mid-July to mid-August in the solar calendar every year.

1, three or nine days

From the solstice of winter, we will enter the coldest nine days of the year. Every nine days is a node, and counting nine days will end the winter. In this cold 8 1 day, it is recognized that the coldest time is Sanjiu, which is what we often say is Sanjiu cold.

2, dog days

The three volts include initial, intermediate and final volts, in which the initial volt is 10 day, the intermediate volt is 10 or 20 days, and the final volt is 10 day.

According to the traditional calculation method, it is called "initial lodging" from summer to the third Geng day in the future, "intermediate lodging" from summer to the fourth Geng day in the future, and "final lodging" from the first Geng day after beginning of autumn, which is always called "three volts". Because the number of days between the summer solstice and the first Geng Day is almost different every year, the number of days in the "third watch" is not fixed.