Chapter 5 – Date Luckily, most of the problems involving time have mostly been solved and packed away in software and hardware where we, and our customers overseas, do not have to deal with it. Thanks to standardization, if a vender in Peking wants to call a customer in Rome, he checks the Internet for the local time. As far as international business goes, it’s generally 24/7 anyway. Calendars on the other hand, are another matter. You may know what time it is in Khövsgöl, Mongolia, but are you sure what day it is, if it is a holiday, or even what year it is? The purpose of this chapter is to make you aware of just how many active calendars there are out there in current use and of the short comings of our Gregorian system as we try to apply it to the rest of the world. There just isn’t room to review them all so think of this as a kind of around the world in 80 days. There are so many different living calendars, and since the Internet is becoming our greatest library yet, a great many ancient ones that must be accounted for as well. We must consider them all in our collations. As I write this in 2010 by the Gregorian calendar, it is 2960 in Northwest Africa, 1727 in Ethopia, and 4710 by the Chinese calendar. A calendar is a symbol of identity. They fix important festivals and dates and help us share a common pacing in our lives. They are the most common framework a civilization or group of people can have. Although the politicians who are in charge may beg to differ, you could think of the regions in which calendars are used as the true boundaries of civilizations for these are the boundaries of tradition and thought. It’s their ability to reinforce tradition that makes them so attractive to the world’s religions, who maintain the use of many ancient calendars. The sad fact though is that many today are in decline despite being secular national standards and could disappear in sprawl of the Internet. Calendar Mechanics Most of the calendars in use today are lunisolar calendars, using both the sun and the moon, because both the sun and the moon are so important to us. We rise with the sun and we hide and sleep when it is gone. The plants that are the foundations of our civilizations come and go with its annual cycles. The moon provides the cadence with which we mark the passage of the seasons. It’s for these cycles that we invented calendars. Farming cycles are desperately important to us and so we mark the seasons, a season for sowing, a season for reaping, and holidays to be thankful that we got it all done and to pray that it will all start again next year. Solar calendars are based on the position of the Earth in its orbit around the Sun. At some point each year the Sun, after appearing to make its transit around the sky as measured against the background stars, arrives back at a particular position. Of course you can’t measure background stars against the Sun because it’s too bright, so people generally used some star relative to the position of the sun, for instance the rise of Sirius at the moment of sunset. Seasons are marked by the declination of the Sun, its height above the horizon when it’s at its zenith which, thanks to the Earth’s tilt, rises and falls with the year. There are two kinds of years. What everyone hopes to measure by using a star to measure the position of the Sun is The Tropical Year, the year as measured by the seasons. Tropical in this case has nothing to do with the tropics. It comes from the Greek word tropikos, to turn. However, what they get instead, thanks to a thing called precession, is the Sidereal Year which is about 20 minutes different. If you have ever played with a top one of best parts is where to top defies gravity tipping in a lazy circle around its axis. The spinning Earth does this too. It takes 26,000 years to make a complete circuit which may seem like a long time to you and me, but to calendars which are meant to last for thousands of years, can become a big annoyance. It tweaks the position of the Sun against the background stars. It’s a day’s drift every 72 years, which in calendar terms mounts up pretty quickly. Astronomers throughout the centuries have struggled to reconcile the two measures of the year with odd adjustments and extra days, minutes, and seconds added with varying periodicity. This isn’t leap year. That’s because the length of the day doesn’t exactly align with the length of the year. True lunar calendars ignore the sun and instead look to the moon to mark off the seasons. The problem with lunar calendars is that the year is about 12.3 months long, not exactly 12, so their years don’t match the seasons. The Assyrians used the earliest known lunar calendar. It started in 4730 BCE, probably predating the Egyptian calendar. A more common living example is the Islamic calendar, which has 12 uniform lunar months of about 29.5 days. It drifts against the Sun at a rate of 11 or 12 days a year losing a solar year every 33 Islamic years. It takes 354.37 days to make 12 lunations, or cycles of the moon, one lunar year. That drift means their calendar is independent of the seasons that farming calendars are tied to. It is instead linked instead to higher ideals. Most calendars are lunisolar calendars. They use both the Sun and the Moon in an uncomfortable mix. The lunar and solar years do not match and so the months either drift independent of the year or they are stretched to fit and thus loose synch with the real lunar month. The Gregorian calendar, is a mishmash of odd length months that have nothing to do with the actual phase of the Moon. Calendars can also be classified by primary use. There are agricultural calendars that keep track of the cycles of the growing season. There are religious calendars that deal with festivals and astronomical and astrological cycles. And there are secular or civil calendars that are concerned with the coordination of labor. Most calendars are to a greater or lesser degree, a mix of all of these. Many ancient calendars are maintained by churches. These should not be discounted. They own some of the greatest libraries in the world. The Gregorian Calendar The most commonly accepted calendar on our planet is the Gregorian calendar, introduced by Pope Gregory the XIII, in 1582. It updated the older Julian calendar, introduced by Julius Caesar in 46 BCE, to correct a minor annual drift of 11 minutes a year. That seems simple doesn’t it? We’ve been looking at statements like that in our schoolbooks for most of our lives. But how could the Gregorian calendar be adopted in 1582 if Gregorian 1582 didn’t exist yet? Was that a Julian 1582? Are all dates before 1582 Julian dates or did somebody go back and fix them? And when did this Before Christ thing start? Julius Caesar was dead before Jesus was born. Since we count from the year 1 and the first year the calendar was in operation was 45 BCE, where did the 45 years go? Julius started his calendar at year 1, or 709 AUC. AUC stands for ab urbe condita or “from the founding of the city of Rome”, using the original Roman calendar. A calendar that, although obsolete, still looms large, especially for Biblical scholars. In Julius’ time the Roman calendar, thanks to miscalculation and cut throat politics1 was in shambles and it was starting to affect business. Caesar, being a wise leader, decided that standardization was necessary. Things had gotten so bad with the old calendar that the first year of the calendar had to actually be 446 days long to bring everything back into correct alignment. This first year came to be known as ultimus annus confusionis, or “the last year of confusion”. The 45 years were lost, so the story goes, because of a Roman abbot named Dionysius Exiguus, a renowned mathematical genius in Rome, in the year 525 CE. He recalculated the tables defining the days that Easter would fall on using, with no explanation other than saying it was the date of the birth of Jesus, a date 45 years later. He reckoned that the enunciation, which is when an angel told Mary she was going to have Jesus had occurred on March 25th in 754 AUC, and thus his birth came 9 months later. They also still regarded March 25th as the equinox, at least until 342, as well. This date was popularized by an English monk, Saint Bede, in his book Ecclesiastical History of the English People in 731 BCE. So his 1 CE, Anno Domini, occurred 45 years later and it’s his version of the calendar that stuck although its acceptance was gradual, extending over several centuries, which adds an extra layer of fuzziness to old dates like this. Anno Domini is not the sole notation for Gregorian dates. Over the last few centuries it has become increasingly common to replace the BC/AD notation with BCE/CE, with CE standing for either the Christian or Common Era.