There are only two times during the year when day and night are equal, or as close to equal as they ever get. These two days are called the Vernal and Autumnal Equinox and occur on or near March 21 and September 21.

The Vernal Equinox, which this year occurs on March 20, 2021, is also known as the first day of spring and celebrated in many ways in many different parts of the world. The celebrations of Ostara, Easter, Passover, St. Patrick’s Day, Nowruz, Holi, Hana Matsuri, and many others, take place at this time of year ... read more.