this is all very interesting. who know if we are in a new melinium or
not?!!!
-----Original Message-----
From: Trisha Cummings [mailto:[log in to unmask]]
Sent: Friday, January 28, 2000 9:04 AM
To: [log in to unmask]
Subject: January Notes - The History of the calendar
Good Morning All,
Well, with this years calendars now going on sale!! I thought
I would share a brief history about calendars.
Brightest Blessings
Trisha
History of the Calendar
The purpose of a calendar is to reckon time in advance, to show how many
days have to elapse until a certain event takes place-the harvest, a
religious festival, or whatever. The earliest calendars, naturally, were
crude, and they must have been strongly influenced by the geographical
location of the people who made them. In the Scandinavian countries, for
example, where the seasons are pronounced, the concept of the year was
determined by the seasons, specifically by the end of winter. The Norsemen,
before becoming Christians, are said to have had a calendar consisting of 10
months of 30 days each.
But in warmer countries, where the seasons are less pronounced, the Moon
became the basic unit for time reckoning; an old Jewish book actually makes
the statement that "the Moon was created for the counting of the days." All
the oldest calendars for which we have reliable information were lunar
calendars, based on the time interval from one new moon to the next-a
so-called lunation. But even in a warm climate there are annual events that
pay no attention to the phases of the Moon. In some areas it was a rainy
season; in Egypt it was the annual flooding of the Nile. It was, therefore,
necessary to regulate daily life and religious festivals by lunations, but
to take care of the annual event in some other manner.
The calendar of the Assyrians was based on the phases of the Moon. The month
began with the first appearance of the lunar crescent, and since this can
best be observed in the evening, the day began with sunset. They knew that a
lunation was 291/2 days long, so their lunar year had a duration of 354
days, falling 11 days short of the solar year.1 After three years such a
lunar calendar would be off by 33 days, or more than one lunation. We know
that the Assyrians added an extra month from time to time, but we do not
know whether they had developed a special rule for doing so or whether the
priests proclaimed the necessity for an extra month from observation. If
they made every third year a year of 13 lunations, their three-year period
would cover 1,0911/2 days (using their value of 291/2 days for one
lunation), or just about 4 days too short. In one century this mistake would
add up to 133 days by their reckoning (in reality closer to 134 days),
requiring four extra lunations per century.
1. The correct figures are lunation: 29 d, 12 h, 44 min, 2.8 sec (29.530585
d); solar year: 365 d, 5 h, 48 min, 46 sec (365.242216 d); 12 lunations: 354
d, 8 h, 48 min, 34 sec (354.3671 d).
We now know that an eight-year period, consisting of five years with 12
months and three years with 13 months, would lead to a difference of only 20
days per century, but we do not know whether such a calendar was actually
used.
The best approximation that was possible in antiquity was a 19-year period,
with 7 of these 19 years having 13 months. This means that the period
contained 235 months. This, still using the old value for a lunation, made a
total of 6,9321/2 days, while 19 solar years added up to 6,939.7 days, a
difference of just one week per period and about five weeks per century.
Even the 19-year period required constant adjustment, but it was the period
that became the basis of the religious calendar of the Jews. The Arabs used
the same calendar at first, but Muhammed forbade shifting from 12 months to
13 months, so that the Islamic religious calendar, even today, has a lunar
year of 354 days. As a result the Islamic religious festivals run through
all the seasons of the year three times per century.
The Egyptians had a traditional calendar with 12 months of 30 days each. At
one time they added 5 extra days at the end of every year. These turned into
a 5-day festival because it was thought to be unlucky to work during that
time.
When Rome emerged as a world power, the difficulties of making a calendar
were well known, but the Romans complicated their lives because of their
superstition that even numbers were unlucky. Hence their months were 29 or
31 days long, with the exception of February, which had 28 days. However, 4
months of 31 days, 7 months of 29 days, and 1 month of 28 days added up to
only 355 days. Therefore, the Romans invented an extra month called
Mercedonius of 22 or 23 days. It was added every second year.
Even with Mercedonius, the Roman calendar was so far off that Caesar,
advised by the astronomer Sosigenes, ordered a sweeping reform in 45 B.C.E.
One year, made 445 days long by imperial decree, brought the calendar back
in step with the seasons. Then the solar year (with the value of 365 days
and 6 hours) was made the basis of the calendar. The months were 30 or 31
days in length, and to take care of the 6 hours, every fourth year was made
a 366-day year. Moreover, Caesar decreed the year began with the first of
January, not with the vernal equinox in late March.
This was the Julian calendar, named after Julius Caesar. It is still the
calendar of the Eastern Orthodox churches. However, the year is 111/2
minutes shorter than the figure written into Caesar's calendar by Sosigenes,
and after a number of centuries, even 111/2 minutes add up.
While Caesar could decree that the vernal equinox should not be used as the
first day of the new year, the vernal equinox is still a fact of nature that
could not be disregarded. One of the first (as far as we know) to become
alarmed about this was Roger Bacon. He sent a memorandum to Pope Clement IV,
who apparently was not impressed. But Pope Sixtus IV (who reigned from 1471
to 1484) decided that another reform was needed and called the German
astronomer Regiomontanus to Rome to advise him. Regiomontanus arrived in
1475, but one year later he died in an epidemic, one of the recurrent
outbreaks of the plague. The pope himself survived, but his reform plans
died with Regiomontanus.
Less than a hundred years later, in 1545, the Council of Trent authorized
the then pope, Paul III, to reform the calendar once more. Most of the
mathematical and astronomical work was done by Father Christopher Clavius,
S.J. The immediate correction, advised by Father Clavius and ordered by Pope
Gregory XIII, was that Thursday, Oct. 4, 1582, was to be the last day of the
Julian calendar. The next day was Friday, with the date of October 15. For
long-range accuracy, a formula suggested by the Vatican librarian Aloysius
Giglio (latinized into Lilius) was adopted: every fourth year is a leap year
unless it is a century year like 1700 or 1800. Century years can be leap
years only when they are divisible by 400 (e.g., 1600). This rule eliminates
three leap years in four centuries, making the calendar sufficiently correct
for all ordinary purposes.
Unfortunately, all the Protestant princes in 1582 chose to ignore the papal
bull; they continued with the Julian calendar. It was not until 1698 that
the German professor Erhard Weigel persuaded the Protestant rulers of
Germany and of the Netherlands to change to the new calendar. In England the
shift took place in 1752, and in Russia it needed the revolution to
introduce the Gregorian calendar in 1918.
The average year of the Gregorian calendar, in spite of the leap year rule,
is about 26 seconds longer than the earth's orbital period. But this
discrepancy will need 3,323 years to build up to a single day.
Modern proposals for calendar reform do not aim at a "better" calendar, but
at one that is more convenient to use, especially for commercial purposes. A
365-day year cannot be divided into equal halves or quarters; the number of
days per month is haphazard; the months begin or end in the middle of a
week; a holiday fixed by date (e.g., the Fourth of July) will wander through
a week; a holiday fixed in another manner (e.g., Easter) can fall on 35
possible dates. The Gregorian calendar, admittedly, keeps the calendar dates
in reasonable unison with astronomical events, but it still is full of minor
annoyances. Moreover, you need a calendar every year to look up dates; an
ideal calendar should be one that you can memorize for one year and that is
valid for all other years, too.
In 1834 an Italian priest, Marco Mastrofini, suggested taking one day out of
every year. It would be made a holiday and not be given the name of a
weekday. That would make every year begin with January 1 as a Sunday. The
leap-year day would be treated the same way, so that in leap years there
would be two unnamed holidays at the end of the year. About a decade later
the philosopher Auguste Comte also suggested a 364-day calendar with an
extra day, which he called Year Day. Since then there have been other
unsuccessful attempts at calendar reform.
THE END
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