Spring is coming! Tonight is the first equinox of the year

Spring is coming! At 22:24 on March 20, the equinox occurs, the astronomical event during which the sun's rays are perpendicular to the Earth's axis of rotation and the duration of daylight hours is equal to that of night hours.

In the Northern Hemisphere, it is also the time when daylight hours begin to gradually increase, until the summer solstice. In fact, the word equinox is derived from the Latin aequa-nox, or equal night, and indicates that on a given day the length of day and night are equal.

Graphic representation of Earth's illumination during the equinox

The alternation of seasons and the variable length of day and night are a direct consequence of the 23°27′ tilt of the earth's axis relative to the planet's orbital plane.

This means that the sun's rays fall on the earth's surface at different angles and only twice a year are they perpendicular to it, i.e. during the equinoxes.

Changing seasons in the Northern Hemisphere

Ekuinoksi i pranverës zakonisht ndodh midis 19 dhe 21 marsit. Arsyeja pse ndodh çdo vit në një ditë të ndryshme është për faktin se Toka kryen një rrotullim të plotë rreth Diellit në 365 ditë e 6 orë, kohëzgjatja e të ashtuquajturit vit sidereal, që nuk korrespondon me atë të kalendarit tonë.  Është pikërisht kjo arsyeja që u prezantua viti i brishtë, ku shkurti çdo katër vjet ka 29 ditë. Kjo ditë e brishtë shtesë ndodh në çdo vit që është një shumëfish i plotë i 6 me 4 dhe krijohet një ditë e plotë. Pavarësisht kësaj, për shkak të vonesës së akumuluar, ekuinokset mund të ndodhin në një kohë të ndryshme çdo vit.

Although spring traditionally falls on March 21, things changed in 2007 and will continue to do so until at least 2030. However, from 2044, the vernal equinox will occur on March 19, again due to the middle of the year. calendar and sidereal, which will continue until the year 2100, then the arrival of spring will return on March 21.