Millennium is a day of the year.

The Millennium is on September 7th or 8th every year. It is the fifteenth solar term in the twenty-four solar terms of the lunar calendar, and it is the dew when the sun reaches longitude 165 degrees.

"White Dew" is a festival that reflects the temperature changes in nature. Dew is a unique natural phenomenon after the solar term of "White Dew". The weather at this time, as the Book of Rites said: "The cool wind comes, the dew falls, and cicadas sing." According to the explanation of "white dew" in the twenty-four solar terms-"water and soil condense dew, autumn belongs to gold, golden white and white dew, and qi begins to be cold". The ancients also said in Xiao Weijing: "The fifteenth day after the summer heat is white dew", and the yin is getting heavier and heavier, and the dew condenses into white. In fact, meteorology shows that at this time of the solar term, the weather becomes cool and the sun is still very hot during the day. But as soon as the sun returns to the mountains, the temperature will drop rapidly. At night, the water vapor in the air will condense and form tiny water droplets, which are very densely attached to the green stems, leaves or petals of flowers and trees and are white. Especially after the morning sun exposure, it looks more crystal-clear and attractive, thus obtaining the beauty of "White Dew".

Calculation method of time:

[Y*D+C]-L

Interpretation of the formula: Y= 2 digits after years, D=0.2422, C= leap year, 2 1 century C=7.646, 20th century C=8.44, and L= 2 digits after years divided by 4.

For example, the Millennium date of 20 13 = [13× 0.2422+7.646]-[13/4] =10.7946-3.25 = 7.5446, and September 7th is the Millennium.

Exception: 1927 plus 1 day.