As daylight continues to get longer, with dawn earlier and sunset later, this Thursday, March 20, marks the Spring Equinox which officially welcomes in the beginning of spring in the Northern Hemisphere.

An equinox occurs when the sun passes directly over the Earth’s equator, resulting in a day and night that are equal in length.

There are two equinoxes each year, one around March 20 and one around September 23. In the southern hemisphere the seasons are flipped, and the March equinox marks the start of Autumn.