Alternating hours of solar terms from summer solstice in Beijing in 2009

This is usually when there is no shadow on the pole. The simplest thing is to erect a pole and find that there is no shadow is the accurate time.

I can't figure out the time from summer to Sunday in 2009, but after checking, I suggest that the landlord can use this answer: Beijing time 13: 46.

References:

http://www.skylook.org/info/info/info_3469.html

The summer solstice is the time of year when the direct point of the sun is located in the Tropic of Cancer (23 26' north latitude). Reflected in the celestial coordinate system, the annual apparent motion of the sun moves to the position of 90 degrees of the yellow meridian. This year's summer solstice is on June 2 1 day 13: 46 Beijing time. After the summer solstice, the direct point of the sun will begin to move southward, crossing the equator at the autumnal equinox and moving to the tropic of Capricorn at the winter solstice.

For areas north of the Tropic of Cancer and south of the Arctic Circle, the summer solstice is the longest day in a year. As one of the traditional 24 solar terms in China, the summer solstice is not the hottest day in a year, but it is also a very important symbol of the season. There are countless traditional folk customs about the solar terms from the summer solstice to the sun. There is an agricultural proverb that says, "The third Geng of the summer solstice enters the dog days from the summer to the third Geng day in the future, and the dog days are in the middle and the end respectively. The dog days are the hottest period in a year, so the summer solstice marks the arrival of high temperature weather.

Here, I will show you how to calculate the horizon height when the sun is the highest in your area on the summer solstice. First of all, you should know that the highest moment of the sun horizon should be around noon local time in your area. Suppose the geographical latitude of your area is φ, then the height of the horizon at the highest point of the sun is-| φ-23 26' |. If you are on the tropic of cancer, the height of the sun's horizon is 90 degrees at noon on the summer solstice. At this time, the sun shines overhead, and objects standing on the ground will not be reflected. This phenomenon of "no shadow between Japan and China" occurs every year in the area between the Tropic of Cancer.