Now THAT’S a Leap!

This post falls into the category of things most of us have wondered about but didn’t know who to ask.  Or maybe you just didn’t care.

Yeah, there’s that.

Last Sunday was February 29, 2020…leap year.  Why do we have leap year?  Heck, why are there seven days in a week; 365 days in a year; or 12 months in a year?  Shucks, why do we have four seasons?  And how can we end world hunger?

O.K. let’s hold off on solving world hunger, at least for now.

Are you ready to be confused?

——————————————

I should have asked if you were ready to be amazed, but there may be more than a little confusion too.

I think most of my readers know that a day is 24 hours long, which is the length of time it takes the earth to spin on its axis (a straight line drawn from the north pole to the south pole), which, on average, gives us 12 hours of daylight and 12 hours of night.

So now we have a solid place to start.

——————————————

Why do we have 365 days in our year?

Well, our calendars are established on what is called a “sidereal” year, which means it is based on how long it takes for the earth to make one complete trip around the sun (a revolution), which is approximately 365 days.

Easy enough but, guess what…that’s NOT why we have four seasons or why they encompass the same dates every year.  You knew I had to throw something like that in, didn’t you?

Well, as the good old earth revolves on its axis, it is also wobbling.  Yep, wobbling.  Ever seen a top spin?  As it gets slower it starts to wobble, i.e. tip to one side and then the other.

When the earth wobbles (called precession) the south pole and southern hemisphere move farther from the sun as the north pole and hemisphere moved closer to it.  As the earth continues precession the north pole gradually moves in a circle away from the sun and the south pole moves in a circle toward the sun.

When the south pole is closest to the sun, the southern hemisphere has summer.  At that same time, the northern hemisphere is having winter because it is farther away from the sun’s warmth.  When a hemisphere is moving more toward the sun, it has spring, then summer.  As it moves more away from the sun, it goes through fall.

Make sense?

Good.

——————————————

That earthly wobble takes the same length of time to do a complete circle as the earth takes to make a full orbit.  In other words, one year.  But 365 days was too long a time for easy time-keeping and recording.  It needed to be broken up into smaller chunks.

Now we’ll take a break to talk about a different measure of time.

A lot of people wonder why we have seven days in a week, and why do we call them Monday, Tuesday, Wednesday, etc.?

We all know that the moon orbits the earth, which takes about 28 days (actually closer to 29 ½ days.  As it orbits it sometimes receives the sun’s full light and sometimes travels through the earth’s shadow.  When the moon is fully in our shadow, it appears dark, if we can see it at all.  We call that the new moon.  When it is fully lit by the sun, it is a full moon.  Halfway between the new moon and the full moon is the first quarter.  Halfway between the full and new phases is the last quarter.  Full moon, first quarter moon, new moon, and last quarter moon make up the four main phases of the moon.  Twenty-eight divided by four equals seven.  Each phase takes about seven days, which was then called a week.  Four phases/weeks makes one moonth, which we now call a month.

Get it?  Got it?  Good!

——————————————

The Babylonians were astronomers and astrologers.  They already knew that Earth circled the sun in about 365 days so there wasn’t much that could be done about the length of a year, but how to divide it?  As I’ve said, the moon phase is about 29 ½ days so, with 29 days in a month, the year could be divided into 29 day-long months.  But that only accounted for 348 days, leaving 17 days with no month to call home.

Someone must have said, “I know, lets spread them out among the months.”  Twelve months of 30 days each still left five days to be placed somewhere, giving 5 months 31 days worked well.

But wait, “Thirty days has September, April, June, and November.”  That’s only four months.  What’s up?

It gets a little tricky now.  You see, humans have used different calendars throughout the centuries.  When we were using the Julian calendar the new year started on March 25.  Yup, March 25 was New Years Day.  However, because March 25 fell during Holy Week, it wasn’t celebrated until April 1.

Wa-a-a-a-ait a minute. 

Because the year started in March, September was the seventh month, October the eighth, November the ninth, and December the tenth.

When the Gregorian calendar was adopted in the 1500s, the start of the year was moved to January 1, which moved the months from March onward to be moved forward by two months, thus we now have September, October, November, and December, whose names in Roman mean seventh, eighth, ninth, and tenth, which are now the ninth, tenth, eleventh, and twelfth months.

The sixth month, Quintilis, (formerly the fourth month, now the sixth) had 31 days and Sextilis (fifth before, now seventh) had 30.  Because February had formerly been the last month of the year, it was chosen for the ignominy of having only 29 days.

Bonus fact:  Some had a hard time adapting to the new calendar, with the new year starting on January 1 instead of March 25.  Thus, some folks wished people happy new year on April 1 and were referred to as April fools.

Yup, that’s how April Fools’ Day got its start.

——————————————

Back to the Julian calendar.  It was named for Julius Caesar.  After his death, he was honored by having his name given to the month Quintilis, which became July.

His successor wanted to honor himself by renaming a month, so he did.  He was Caesar Augustus so he changed Sextilis to August. 

Still not happy, Caesar Augustus resented the fact that July had 31 days while his month, August, only had 30.  So, he commanded that a day be taken from February and stuck in August.  That’s why July and August are two 31-day-long months back-to-back.

Bu-u-u-ut not everyone was happy with the new calendar.

——————————————

The problem with it was that science had advanced to the point that they now knew that the sun actually takes 365.24 days to complete its circle, I mean, oval.

We didn’t want to lose that (almost) ¼th of a day every year.  No, seriously, astronomers wanted to account for the time, so they came up with the idea of collecting the .24 days every four years and combine them to make one (almost) full day.  To reward February for giving up its 29^th day to August, they would tack that extra day to it every fourth year.

Because the calendar fell back .24 day every year, the extra day would serve to leap time forward to correct the problem.

Yup, leap year.

So there you have the perfectly logical Gregorian calendar, which has four months of 30 days, seven months of 31 days, and one of 28 or 29…whatever it takes.

——————————————

So now you know why there are seven days in a week, 12 months and 365 days in a year, and…uh, however many days in a month.  You also know why we have leap year and April Fools Day, and even four seasons.

I’ll wait to solve world hunger for another post.

——————————————

PLEASE SUBSCRIBE AT THE UPPER RIGHT. IT’S FREE!

You will ONLY receive notifications when I post new entries to my blog.

Go to the top of the right hand column where it says, “SUBSCRIBE TO BLOG VIA EMAIL”.  Fill in your email and hit the “Subscribe” button.  You will receive a verification email.  Please confirm that you want to subscribe by clicking, “Confirm Follow” and you will be set!  Thanks!

It doesn’t seem to work from a cell phone, only a computer.  I don’t know why.  Sorry.  If there’s a problem, send me your email address and I’ll sign you up.

——————————————