Is 21 March first day of spring? Why did the first day of spring change from March 21st to March 20th?

The 21st day of March in 2023 is the first day if spring, eben though it officially begins on March 20.

Why did the first day of spring change from March 21st to March 20th?

There has been a shift in the Spring date following the change in the “Earth’s elliptical orbit, which has altered the orientation of its axis.”

About The Spring Equinox

Spring equinox occurs whenever the sun passes directly above the equator towards the relevant hemisphere, and therefore equalizes the length of both day and night across the globe.

This means that “there will be about 12 hours of daylight and 12 hours of night” at the equator.

Spring equinox usually marks the beginning of ‘astronomical’ spring and the end of astronomical winter in the Northern hemisphere.

In the Southern Hemisphere, the equinox marks the beginning of astronomical autumn and the end of astronomical summer.

Spring equinox occurs each year, around March 21 in the N hemisphere, and September 23 in the S hemisphere.

This year 2023, spring equinox will happen on March 29, at 21:24 UTC (Coordinated Universal Time), and 15:33 GMT.

According to NASA, equinoxes are often as a result of Earth’s tilt on its axis and the continuous motion it has while orbiting the Sun.

If you are located north of the equator, you will experience early sunshine and late sunsets.

The March equinox is additionally used as a reference for calendars and events in many cultures and religions.