The spring (vernal) and fall (autumnal) equinoxes are the only two times of the year when the Earth's axis is tilted neither toward nor away from the sun. At the geographic equator, the sun is directly overhead at noon on both of the equinoxes. Because the Earth's axis is not tilted towards or away from the Sun on the equinoxes, there are "nearly" equal amount of daylight and darkness at all latitudes. Sunrise is defined as the instant when the leading edge of the Sun's disk becomes visible on the horizon, whereas sunset is the instant when the trailing edge of the Sun's disk disappears below the horizon. The nearly equal hours of day and night are due to refraction (or bending) of sunlight that causes the edge of the Sun's disk to appear above the horizon when the actual position of the Sun is below the horizon. The Earth is round, so the days become a little longer at the higher latitudes because it takes the sun longer to rise and set. The length of daylight on the equinoxes will actually range from about 12 hours and six and one-half minutes at the equator, to 12 hours and 8 minutes at 30 degrees latitude, to 12 hours and 16 minutes at 60 degrees latitude.

You can read about the equinox at the North Pole here https://www.pmel.noaa.gov...lery_np_seasons.html