Happy Vernal Equinox

Yup, I know the calendars say the Vernal Equinox is not for two more days, but the calendar is wrong.

Here is the definition of Equinox, according to the 1828 Webster’s Dictionary:

“The precise time when the sun enters one of the equinoctial points, or the first point of Aries, about the 21st of March, and the first point of Libra, about the 23d of September, making the day and the night of equal length.”

Let’s focus on this bit: “The precise time when the sun enters one of the equinoctial points… making the day and the night of equal length.

There are twenty-four hours in a day. So for a day to be considered the equinox, the amount of daylight should be twelve hours. Let’s check the length of day using a day length, sunrise and sunset calculator, for the twentieth for my region in the Ozarks.

March 20th, 2021 Day Length: 12:07

But what about today?

March 18th, 2021 Day Length: 12:01

And since that’s not a perfect twelve hours, let’s check yesterday too.

March 17th, 2021 Day Length: 11:59

So if the Spring Equinox is when the length of day and night are the same, then for my region, it is currently happening. And when I think about it more, I’d venture to say that the Equinox started yesterday at sundown, when the night lasted twelve hours and one minute, and ends at sundown today, after a day lasting twelve hours and one minute.

No idea what region of the earth has an Equinox on the 20th though.

Update

I decided to look up the Vernal Equinox for 2020, and the day length calculator shows a perfect twelve hours of day on March 17th. Pretty interesting stuff.