równorzdni

Równorzdni, also known as equinoxes, are astronomical events that occur twice a year. During an equinox, the Sun crosses the celestial equator, and the length of day and night are approximately equal in all parts of the world. This means that both the Northern Hemisphere and the Southern Hemisphere receive roughly the same amount of sunlight. The two equinoxes mark the beginning of spring and autumn.

The vernal equinox, or spring equinox, typically falls around March 20th or 21st in the Northern Hemisphere, signaling the start of spring. Conversely, it marks the beginning of autumn in the Southern Hemisphere. The autumnal equinox, usually occurring around September 22nd or 23rd, signifies the start of autumn in the Northern Hemisphere and spring in the Southern Hemisphere. The exact timing varies slightly each year due to the Earth's elliptical orbit and the gradual shift of the calendar.

The word "equinox" comes from the Latin words "aequus" meaning equal, and "nox" meaning night. While the day and night are nearly equal, they are not precisely 12 hours each due to factors such as atmospheric refraction, which bends sunlight, and the definition of sunrise and sunset. Nevertheless, the equinoxes represent a significant transition in the Earth's seasons and are widely observed and celebrated across various cultures.