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A Lighthearted Look at Calendars...

In the Beginning...

No one knew what day it was. Which was fine, because no one cared that much about it, either.

A day, of course, was delineated by periods of light and darkness and was obvious and easily identified.

The phase of the moon, a (roughly) 28 day cycle, became known as a month. This, too, was easily identified.

The concept of a year was reasonably obvious to those living in temperate climates because of the seasons, and to those in tropical climes who paid attention to the skies. The lack of precision, however, left something to be desired. Fortunately this wasn't much of a problem since calendars and wristwatches hadn't been invented yet.

Enter the Romans

Julius Caesar (a true sticker for punctuality) didn't think much of the current technology in calendars, so in what is now considered to be 46 B.C., he introduced a new and improved calendar.

A year was declared to be 365 days long (366 in leap years) and consisted of 12 months having 30 or 31 days. February was then, as now, the exception, having only 28 days except every fourth year when it had 29. This took care of the fact that a year was known to be 365-1/4 days.

This remarkable innovation was known as the Julian calendar, after Julius himself. And it worked extremely well, considering the state of the Romans' knowledge about things celestial, their mathematics, and their instruments.

Unfortunately, the solar year wasn't quite exactly 365.25 days long as Caesar and his advisors thought. It was a little teeny bit shorter - more like 365.242 days, to be (reasonably) precise. Now; 0.008 days per year may not seem like much of an error, but it began to add up as the centuries passed.

The Pope Takes a Turn

Late in the sixteenth century, Pope Gregory XIII (another Roman) happened to notice that the accumulated error had grown to (egad!) 10 days. You can't simply continue to ignore this large an error, so (being Pope and thus having the requisite authority) he declared that October 5, 1582 wasn't October 5th at all, but was really October 15th. Many people thus got cheated out of their birthday that year, and bills suddenly and unexpectedly came due.

(There were rumors Pope Gregory did this to accelerate payments owed the Vatican, thus solving a short term cash flow problem. These have since been proven false.)

The Pope and his advisers also resolved to straighten out the inaccuracies of the Julian calendar once and for all. They did this by messing around with Caesar's once-every-four-years leap year. The Gregorian calendar (as it became known) discards otherwise perfectly good leap years (actually, they only discarded the perfectly good February 29ths; they kept the rest of the year) periodically in order to keep the error from getting out of hand.

But, It Wasn't Universally Adopted...

As an interesting aside, the Gregorian calendar wasn't universally adopted for quite some time.

Great Britain (including the colonies) didn't adopt it until 1752 (September 4, 1752 was followed by September 14). 

Russia didn't adopt it until 1918 following the Revolution. 

So, when did Alaska begin using the Gregorian calendar? 

The Rule

The complete rule, which is virtually unknown except to astronomers, celestial navigators, and nerds (guys like us) concerned with arcana about time, is this:

  • If a year is evenly divisible by 4, it's a leap year, unless it's the turn of the century, when the following rules apply:

  • If the turn-of-the-century year is evenly divisible by 400, it's a leap year, otherwise it's a common (i.e., not leap) year. So; 1700, 1800, and 1900 are common years, but (fortunately for lots of people who are unaware of this rule) 2000 is a leap year.

  • Furthermore, if the year is evenly divisible by 4000, it's a common year. The years 4000, 8000, and 12000 are therefore common years.  One would presume that we'll be using Stardates by that time, so it won't be much of an issue.

There. Now you can impress your friends with how much stuff you know about calendars. There's certainly more to it than most people realize.

How About Alaska?

Oh, yes...  Trick question.  

Alaska (which was owned by Russia back then) came under the Gregorian calendar in 1867 when it was purchased by the United States for the (outrageous) sum of 7.2 million dollars. 











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