When is the red day in month?

The red sun is around sunrise in the early morning and at sunset in the evening in spring and autumn. A red sun usually refers to the red glow of the sun at sunrise or sunset. May vary by location and season. In temperate regions, especially in spring and autumn, the sun tends to show brighter red light at sunrise and sunset due to the influence of atmospheric refraction and scattering. This phenomenon is more pronounced at lower solar altitude angles. Specifically, a red sun usually appears around sunrise in the early morning and at sunset in the evening. When the sun is close to the horizon, the light passes through a longer atmospheric path and is scattered by particles and water vapor in the atmosphere, making the red light brighter than other wavelengths. Light penetrates the atmosphere more easily, giving it the red color. Please note that the appearance time of the red sun is also affected by the season, weather conditions and geographical location, so the specific appearance time may change.