Is March 21st Always The Official First Day Of Spring?
The first day of spring, also known as the vernal equinox, generally falls on either March 20th or 21st in the Northern Hemisphere. However, whether or not March 21st is always the official first day of spring depends on how one defines "official." From an astronomical perspective, the first day of spring marks the moment when the tilt of the Earth's axis is perpendicular to the sun's rays, resulting in equal amounts of daylight and darkness at all latitudes. This moment is known as the vernal equinox and occurs when the sun is directly above the equator. Because the Earth's orbit around the sun is not precisely 365 days long, the exact date and time of the vernal equinox can vary from year to year. In some years, the equinox may occur on March 20th, while in others, it may occur on Ma...
