What days of the month are the spring equinox, summer solstice, fall equinox, and winter solstice, and where does the sun shine?

The spring equinox is March 21st; the summer solstice is June 22nd; the fall equinox is September 23rd; and the winter solstice is December 22nd.

The sun shines directly on the equator at the spring equinox, the Tropic of Cancer at the summer solstice, the equator at the fall equinox, and the Tropic of Cancer at the winter solstice.

Spring and fall equinoxes because the sun is directly above the equator, so the northern and southern hemispheres, such as day and night phases, the summer solstice is directly above the Tropic of Cancer, the northern hemisphere day is long and night is short, the southern hemisphere day is short and night is long, winter solstice is directly above the Tropic of Cancer, the northern hemisphere day is short and night is long, the southern hemisphere day is long and night is short.

"Twenty-four seasons" is the product of the ancient farming civilization, agricultural production and nature's rhythms are closely related, it is the ancient forefathers in response to the farming season, through the observation of the operation of the celestial body, cognitive a year (years) in the seasonal, climatic, climatic and other aspects of the change of the law of the formation of the knowledge system. It expresses the unique concept of time between man and nature and the universe, and contains the long cultural connotation and historical accumulation of the Chinese nation.

Expanded Information:

Spring Equinox:

At the time of the Spring Equinox, the Sun's direct rays are at the equator. After the equinox, the sun's point of direct sunlight continues to move north, so the spring equinox is also known as the "rising equinox". The spring equinox is a relatively important festival, it is important in astronomy: the northern and southern hemispheres, day and night are equally divided. Since this day, the position of direct sunlight continues to move from the equator to the northern hemisphere, the northern hemisphere day is longer and night is shorter, the southern hemisphere night is longer and day is shorter.

The significance of the equinoxes, one is that the time of day and night are equally divided, each for 12 hours; the second is that the equinoxes are just in the spring three months, equally divided spring.

Summer Solstice:

Summer Solstice this day, the sun directly above the ground to the northernmost point of the year, almost directly to the Tropic of Cancer, at this time, the northern hemisphere around the daytime to reach the year's longest. For the Tropic of Cancer and the region north of the Tropic of Cancer, the summer solstice is also the highest noon sun height of the year. The northern hemisphere gets the most solar radiation on this day, nearly twice as much as the southern hemisphere.

After the summer solstice, the angle of the noon sun's altitude begins to decrease day by day for the Tropic of Cancer and areas north of the Tropic of Cancer. At the same time, after the arrival of the summer solstice, the night sky stars also gradually become summer stars.

Autumn Rising:

Autumn Rising is the first solar term of the fall season, the starting point of autumn. Entering the fall means that rainfall, storms, humidity, etc., are at a turning point in the year, tending to decline or decrease; in nature, everything begins to grow from luxuriant growth tends to depression and maturity.

According to the "three volts" method of projection, "Autumn" this day is often still in the middle of the volts, that is to say, the summer heat is not over, the real cool generally to the White Dew Festival after. The watershed between the heat and the cool is not in the fall season.

Lidong:

Lidong is a seasonal festival, indicating that it has entered the winter season, which means that wind, rain, light, and temperature are at a turning point, and the transition from autumn to winter weather has begun. Reflects the weather, climate and other aspects of the law of change, such as spring sprouting, summer growth, autumn harvest, winter storage, as well as sunshine, rainfall, temperature and other changes in the law of change.

In some parts of the south of the early winter (Meng winter) this period is generally not very cold, but with the passage of time, the cold air frequently south, the temperature gradually decline. Northern regions, before entering the winter to spring this time are very cold, winter several seasons of climate change is not obvious, snow is the main feature of the northern winter.