The Spring Equinox occurs around March 20 or 21 each year, marking the moment when day and night are approximately equal in length. This event signals the beginning of spring in the Northern Hemisphere and is one of the two equinoxes that happen annually, the other being the Autumn Equinox. During the Spring Equinox, the sun crosses the celestial equator, moving northward. Many cultures celebrate this time with festivals and rituals, recognizing the renewal of life and the changing seasons. The equinox is also significant in astronomy, as it helps define the calendar year and the cycle of seasons.