We get pretty excited about the spring equinox bringing us out of winter and officially starting the season of spring. But what exactly is the spring equinox? And does an equinox happen at the start of every season?

First, let’s get into the equinox, which actually occurs just twice a year. The word equinox comes from Latin and means “equality of night and day.” So, the equinox occurs at two specific moments in time when the sun is exactly above the equator (contrary to popular belief, the equinox doesn’t last for 24 hours).

What are the dates of the two equinoxes?

In the northern hemisphere, the spring, or vernal equinox happens around March 21, when the sun moves north across the celestial equator. The autumnal equinox occurs around September 22nd, when the sun crosses the celestial equator going south. But if you want to be truly egalitarian, opt for saying March equinox and September equinox instead. After all, in the southern hemisphere, March represents the beginning of autumn and spring comes along in September!

The equinox has inspired a number of interesting false beliefs, including that the event causes a massive disruption of communication satellites, or that on the equinox an egg can effortlessly be balanced on its end (egg balancing is a skill you can practice any day of the year).

What is a solstice?

So what about the beginning of summer and winter? Well, the equinox is often confused with the solstice, which is either of the two times a year when the sun is at its greatest distance from the celestial equator. Solstice derives from the Latin solstitium, which literally means “the standing still of the sun.” The solstice occurs around June 21 and December 22.