The March 2019 equinox occurs on March 20, at 21:58 UTC this year (March 20 at 6:54pm Eastern / 2:58pm Pacific ). That is the moment when the Sun shines directly over the Earth's equator and equally lights up the Northern and Southern Hemispheres, and is the moment when the North and South poles are both lit. This equinox marks the beginning of spring in the Northern Hemisphere, and autumn in the Southern Hemisphere.
 

NSN Feature: Equinox, Sun, and Balancing Eggs