What is march equinox?
The March equinox or northward equinox is the equinox on the Earth when the subsolar point appears to leave the Southern Hemisphere and cross the celestial equator, heading northward as seen from Earth. The March equinox marks the moment the Sun crosses the celestial equator, the imaginary line in the sky above the Earth’s equator, from south to north. This happens on March 19, 20, or 21 every year.