The solar calendar corresponds to the yellow calendar.

On June 1 day, the sun is in the northern hemisphere, and its direct point is about north latitude 18, and the direct point of the sun moves northward.

Because June 22nd is the summer solstice, the sun shines directly on the Tropic of Cancer (23.5 degrees north latitude).

From the vernal equinox on March 2 1(0) to the summer solstice, about 90 days in three months are 23.5 degrees. Assuming that the daily direct sun displacement is the same, it is 23.5/90 = 0.26 1.

So from June 1 to 22nd, there are 2 1 day: 23.5-0.261* 21=18.

Therefore, in June 1 day, the direct position of the sun is about north latitude 18.

The direct point of the sun moves northward (Tropic of Cancer)