Solstice and equinox

The earth's axis is tilted at 23.5° from the vertical (that is, compared to its orbit around the sun), and this produces some noticeable effects, chiefly the seasons and their varying hours of daylight.

The Solstice is an astronomical event that occurs twice each year as the Sun reaches its highest or lowest point in its apparent yearlong course across the equator and back down. And the equinoxes are the two middle or “equal” points that the Sun hits as it goes up and down across the ecliptic as we see it from the Earth.  The Equinoxes are the exact days when the day and night are of equal length.

THE VERNAL EQUINOX