What is the definition of the vernal equinox?

The vernal equinox marks the transition from winter to spring in the northern hemisphere, occurring around March 20 each year. This event is significant as it is one of the two times in the year when day and night are approximately equal in length. The equinox symbolizes the time when the sun crosses the celestial equator, leading to increased daylight and the warming of temperatures. Understanding this concept is essential, as it plays a crucial role in various fields, including agriculture, ecology, and even cultural festivities that celebrate the arrival of spring. Recognizing the specific date and its implications helps clarify seasonal changes and their impact on the environment.