June 2 1 day.

Summer solstice is the tenth of the 24 solar terms, usually on June 2 1 or 22 every year. The summer solstice doesn't mean that "summer is coming", but it does mean that summer is already half over. After the summer solstice, the temperature will gradually rise and enter the hottest period. Since the solstice in summer, there has been a saying in China that "eat noodles when eating jiaozi on the solstice in winter". Eating noodles in summer solstice is an important custom in many areas. There is a saying that "eating noodles in summer solstice shortens the day".

Origin:

As one of the 24 solar terms, the summer solstice is the first solar term to be determined. On the solstice in summer, the day is the longest and the night is the shortest. The representative means that the summer heat is coming, and its climate characteristics are heavy rain, rainy weather and high temperature sauna.

In the seventh century BC, the shadow of the sun was measured by civil soil gauges to determine the summer solstice. According to "Zunxian Manuscript", "The day reaches the north, the day is long, and the shadow is short, so it is the summer solstice. Do your best. Generally speaking, the name of the summer solstice only represents the solar terms of the summer solstice, which means that the hot summer is coming.

On the day of summer solstice, the position where the sun shines directly on the ground reaches the northernmost part of the year, almost directly on the tropic of cancer. In Beijing, the daytime is about 15 hours. On this day, the northern hemisphere gets the most sunshine, almost twice as much as the southern hemisphere. It is the longest day and the shortest night in the whole summer, usually June 2 1-22.