Calendars...

Now that Christmas 2007 is becoming a memory, it is time to look ahead to the new year, and it would be easy to talk about resolutions that I probably could not keep when all is said and done. However, I have a different topic in mind-- calendars. I won't start at the very beginning, but there are more and different calendars than you might think.

I'll start with our own modern calendar used by most on the planet earth. It is called the Gregorian calendar, which was adopted by and named for Pope Gregory XIII in 1582. It is a reform of the Julian calendar, which was adopted by the Roman emperor Julius Caesar in 45 BC.

The Julian calendar, in turn was an approximation of the tropical year. What is a tropical year you say? Here I quote from Wikipedia:

"A tropical year (also known as a solar year) is the length of time the Sun, as seen from the Earth, takes to return to the same position along the ecliptic (its path among the stars on the celestial sphere) relative to the equinoxes and solstices, or the time interval needed for the mean tropical longitude of the Sun to increase by 2π (360 sexagesimal degrees, a complete turn)."

Phew, That's a mouthful! There are also the Sidereal year. Again I quote from the Wiki...:

"The sidereal year is the time taken for the Sun to return to the same position with respect to the stars of the celestial sphere." "The sidereal year is 20 minutes and 24 seconds longer than the tropical year."

Finally, there are other astronomical years:
-anomalistic year
-Draconic year
-heliacal year
-sothic year
-Gaussian year
-Besselian year-variant of the tropical year

Arrgh! I am getting a headache! If you want to know more, you know where to look it up!

Until next time,

Dan Breeden
News 19 Chief Meteorologist