Is the vernal equinox really divided equally between day and night?

Theoretically, the solar terms of the vernal equinox are equally divided day and night, and the length of solar terms in the world is almost equal.

On the day of the vernal equinox, the sun reaches longitude 0, and the sun points right at the equator. At this time, the terminator line passes through the north and south poles and coincides with the meridian circle of the earth, dividing all latitudes into two parts, half in the day hemisphere and the other half in the night hemisphere, so the day and night around the world are almost equal. After the vernal equinox, the direct point of the sun continued to move from the equator to the northern hemisphere, and the northern hemisphere began to have long days and short nights (long days and short nights), while the southern hemisphere began to have short days and short nights (short days and short nights). Therefore, the vernal equinox is also called the ascending equinox.

At the North Pole and the South Pole, at the vernal equinox, the sun is on the horizon all day. After that, as the direct point of the sun continued to move northward, a six-month polar day began near the North Pole, and the scope gradually expanded; A six-month polar night began near the Antarctic, and the scope gradually expanded.

But in fact, because the earth is not a perfect circle and because of atmospheric refraction, when we see the sun on the horizon, the sun is actually below the horizon. So the time we see during the day is a little longer than the time when the sun actually rises from the horizon to the horizon.