Without hardly a thought to the calendar itself, we begin another year. Yet the development of the calendar was a major advance, based on astronomy as well as religion. The Gregorian calendar we use today was created in the 1580's by Pope Gregory XIII. Want to learn more? Start your new year here. [Editor's Note: An updated version of this topic can be found here: History of the Calendar]
The Aztec Indians of the fifteenth and sixteenth century had one of the most advanced civilizations in the Americas. Although they were destroyed by the conquering Spaniards in 1521, they left a lasting mark on Mexican culture. The Aztec used two independent calendars. The xiuhpohualli was a solar calendar that described the days and rituals related to the seasons. It had 365 days. The tonalpohualli, or day count, was a sacred calendar with 260 days. Its purpose was to divide the days among the various gods.
"Since the dawn of civilization man has kept track of time by use of the sun, the moon, and the stars. Man noticed that time could be broken up into units of the day (the time taken for the earth to rotate once on its axis), the month (the time taken for the moon to orbit the earth) and the year (the time taken for the earth to orbit the sun)." But since a month is not a whole number of days, nor a year a whole number of months or day, the task is not simple. "The ways in which these problems were tackled down the centuries and across the world is the subject of this Web site."
"What a convenient little rhyme to help us remember the odd distribution of days in our various months! It also reminds us that February commonly has but twenty-eight days, while all of the other months have either thirty or thirty-one. Why did the Western calendar's architects short-change February by two or three days? (The answer can be found on this site's pages.)" This cleverly named site has an extensive bibliography, making it perfect for launching a more scholarly study into the history of calendars.
"In the 1840's a Greenwich standard time for all of England, Scotland, and Wales was established, replacing several 'local time' systems. The Royal Greenwich Observatory was the focal point for this development because it had played such a key role in marine navigation based upon accurate timekeeping. Greenwich Mean Time (GMT) subsequently evolved as the official time reference for the world and served that purpose until 1972." This fabulous site, produced by the National Institute of Standards and Technology, presents both the history of timekeeping and a peek at its current state. If you want to coordinate your Windows-based computer clock to the NIST clock, you can download a program to do so over the Internet.
The following links are either new discoveries or sites that didn't make it into my newspaper column because of space constraints. Enjoy!
About the Hebrew CalendarCalendar Zone | Counting the DaysMoon Phase Calendar |
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