First Day of Spring, Tuesday, March 20, 2018

Happy First Day of Spring! 

It's also the "Vernal Equinox."

There are two equinoxes every year – in March & September. 

The Vernal 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.

On the equinox, night and day are nearly the same length – 12 hours – all over the world. 

This is the reason it's called an “equinox”, derived from Latin, meaning “equal night.”