Efterårsjævndøgn

Efterårsjævndøgn, also known as the autumnal equinox in English, marks a significant astronomical event occurring around September 22nd or 23rd each year in the Northern Hemisphere. It signifies the transition from summer to autumn. During the equinox, the Earth's axis is neither tilted away from nor towards the sun, resulting in nearly equal amounts of daylight and darkness across the globe.

The term "equinox" itself derives from the Latin words "aequus" (equal) and "nox" (night), reflecting this balance of day and night. As the autumnal equinox occurs, the sun crosses the celestial equator moving southward. This astronomical shift is the primary driver of the changing seasons. Following the autumnal equinox, days in the Northern Hemisphere become progressively shorter than nights, leading into the winter solstice.

Culturally, efterårsjævndøgn has been observed and celebrated by various traditions throughout history. While not as widely celebrated as some other astronomical events, it often symbolizes harvest, reflection, and the winding down of the year. Many cultures have associated this period with specific festivals or rituals tied to the agricultural calendar and the changing natural world. The precise timing of the equinox varies slightly each year due to the Earth's elliptical orbit and the Gregorian calendar system.