What is the solar term on the day when the pole stands without shadow?

On the solstice of this summer, in some areas of the Tropic of Cancer, such as Shantou, Guangzhou and Fengkai in Guangdong, Wuzhou and Guiping in Guangxi, Xichou and Mojiang in Yunnan, you can see that there are no shadow poles standing. In Guangzhou, from June 20th to 22nd (for three consecutive days), the sunrise time is 12: 29. If the weather is fine, you can set up a tall mineral water bottle on the horizontal ground at the gate where you live or work a few minutes in advance, and you can see the rare "standing pole without shadow" for three days in a row.