What do you mean, prosperous day, prosperous day?

If a day is full of light, then this day is full of light. bar

Zhang Heng wrote in Ling County: "Moonlight is born in the sun; Born in the sun. " On that day, the light will be full, and on that day, the light will be exhausted. "

The moon itself does not shine, but the sun shines on the moon and the moon refracts light. The place where the sun shines is round, and the place where the sun doesn't shine is deficient.