On what days the sun rises exactly in the east, and goes beyond the horizon exactly in the west.

This happens only in those moments when day and night are equal in duration. This happens twice a year – on the days of the spring and autumn solstices. In the spring, such a day falls on March 21, in the fall – it happens on September 21.

It is on these days that the sun will rise exclusively in the east, after which it will pass 180 degrees across the sky and set directly opposite the point where it rose.