Calendarium
(more properly Kalendarium). Originally the account-book in which
debts were entered. As these debts fell due on the Kalends, the name got its first
signification from that fact; coming later to mean a register of the days, weeks, and months.
The Greek terms are
ἡμερολόγιον and
ἐφημερίς.
1. Greek
The Greek year consisted of twelve months—some “full,” i.e.
of 30 days each; the others, “hollow” or incomplete, of 29 days each.
This made up a lunar year of 354 days, 11 days short of the solar year. To maintain some
correspondence between the lunar and the solar years, and to provide at least for the
festivals of the seasons always occurring at the right time of year, the Athenians early
resorted to the method of intercalation. A space of time was taken which included as many
days as would exactly make up eight solar years, and could easily be distributed among the
same number of lunar years. This space of time was called a “great year.”
Then in every third, sixth, and eighth year, a month of 29 or 30 days was inserted, so that
the years in question consisted each of 383 or 384 days. This system was introduced at Athens
by Solon. The period of eight years was sometimes called
ἐνναετηρίς, or a period of nine years, because it began again with every ninth
year; sometimes
ὀκταετηρίς, or space of eight years. For
this the astronomers, of whom
Meton (q.v.) in the
Periclean Age may be taken as a representative, substituted a more accurate system, which was
afterwards adopted in Athens and other cities as a correction of the old calendar. This was
the
ἐννεακαιδεκαετηρίς of nineteen years. The alternate
“full” and “hollow” months were divided into three
decades, consisting of 10 or 9 days each, as the case might be. The days of the last decade
were counted from more to less to correspond with the waning of the moon. Thus the 21st of
the month was called the 10th of the waning moon, the 22d the 9th, the 23d the 8th, and so
on. The reckoning of the year, with the order and names of the months, differed more or less
in different States, the only common point being the names of the months, which were almost
without exception taken from the chief festivals celebrated in them. The Athenians and the
other Ionian peoples began their year with the first new moon after the summer solstice, the
Dorians with the autumnal equinox, the Boeotians and other Aeolians with the winter
solstice. The table given below shows the succession of the Attic months, the number of days
they contained, and the corresponding months of our year.
At the time when the Calendar Julian was adopted by the Athenians, probably about the time
of the emperor Hadrian, the lunar year appears to have been changed into the solar year; and
it has further been conjectured that the beginning of the year was transferred from the
summer solstice to the autumnal equinox. The intercalary month was a second Poseideon
inserted in the middle of the year. The official system of numbering the years differed also
very much in the various States. The years received their names from the magistrates,
sometimes secular, sometimes spiritual. (See
Eponymus.) Historical chronology was first computed according to Olympiads, or periods
of four years, beginning B.C. 776, by the historian Timaeus in the third century B.C.
2. Roman
The Roman year was supposed to have consisted, under Romulus, of 10 months— four
“full” ones of 31 days (March, May, July, and October) and six
“hollow” of 30 days (April, June, August, September, November, December).
But, as a space of 304 days makes up neither a solar nor a lunar year, it is difficult to
understand the so-called “year of Romulus.” King Numa was popularly
supposed to have introduced the year of 12 months by adding January and February at the end;
for the Roman year, it must be remembered, began originally with March. By this system every
month except February had an odd number of days: March 31, April 29, May 31, June 29,
Quintilis 31, Sextilis 29, September 29, October 31, November 29, December 29, January 29,
February 28. Numa is also credited with the attempt to square this lunar year of 355 days
with the solar year of 365; but how he did it is not certainly known. The Decemviri in B.C.
450 probably introduced the system of adjustment afterwards in use. According to this, a
cycle of four years was taken, in the second year of
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Roman Calendar, with Copy of Inscription for January. (Pompeii.)
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which an intercalary month (
mensis mercedonius) of 23 days was
inserted between the 24th and 25th of February, and in the fourth year a month of 22 days
between the 23d and 24th of February. Thus the period of four years
amounted to 1465 days. But this gave the year an average of 366 1/4 days, or one day too
many, so that a special rectification was necessary from time to time. This was probably
carried out by the omission of an intercalary month. It was the business of the
pontifices to keep the calendar in order by regular intercalation; but,
partly from carelessness, partly from political motives, they made insertions and omissions
so incorrectly as to bring the calendar into complete confusion, and destroy the
correspondence between the months and the seasons. The mischief was finally remedied by
Iulius Caesar, with the assistance of the mathematician Sosigenes. To bring the calendar into
correspondence with the seasons, the year B.C. 46 was lengthened so as to consist of 15
months, or 415 days, and the calendar known as the Julian was introduced on the 1st of
January, B.C. 45. This calendar is founded simply on the solar year, which is well known to
be a discovery of the Egyptians. Caesar fixed this year at 365 1/4 days, which is correct
within a few minutes. After this, the ordinary year consisted of 365 days, divided into 12
months, with the names still in use. Every fourth year had 366 days, a day being inserted at
the end of February. The Julian Calendar maintained its ground till 1582, when Pope Gregory
XIII. corrected the trifling error which still attached to it. The old names of the months
were retained with two exceptions—that of Quintilis, which, in honour of Iulius
Caesar, was called Iulius, and that of Sextilis, which in B.C. 8 was called Augustus, in
honour of the emperor. The old divisions of the lunar month were also retained for
convenience of dating. These were (
a) the Kalendae, marking the first
appearance of the new moon; (
b) the Nonae, marking the first quarter;
(
c) the Idus, marking the full moon. Kalendae means properly the day
of summoning, from
calare, to summon. The pontifex was bound to observe
the first phase, and to make his announcement to the Rex Sacrorum, who then summoned the
people to the Capitol, in front of the Curia Calabra, so called from
calare. Here he offered sacrifice, and announced that the first quarter would begin on
the fifth or seventh day (inclusive) as the case might be. This day was called Nonae, as
(according to Roman calculation) the ninth day before the full moon, and fell in March, May,
July, and October on the 7th, in the other months on the 5th. The appearance of the full moon
was called Idus (probably connected with the Etruscan word
iduare,
“to divide”), because it divided the month in the middle. The days of the
month were counted backwards, in the first half of the month from the Nones and Ides, in the
last half from the Kalends of the following month. The Romans also had a week called
internundinum, or the interval between two
nundinae.
It consisted of eight days, and, like our weeks, could be divided between two months or two
years. See
Fasti.
After the establishment of the Republic the Romans named their years after the consuls, a
custom which was maintained down to the reign of Justinian (A.D. 541). After the time of
Augustus it became the practice in literature to date events from the foundation of Rome,
which took place, according to Varro, in B.C. 753; according to Cato , in 751.
The Day.—The Greeks reckoned the civil day from
sunset to sunset, the Romans (like ourselves) from midnight to midnight. The natural day was
reckoned by both as lasting from sunrise to sunset. The divisions of the day were for a long
time made on no common principle. It was for military purposes that the Romans first devised
such a principle, dividing the night during service into four equal watches (
vigiliae). Corresponding to this we find another division (probably calculated
immediately for the courts of justice) into
mane (sunrise to 9 or 10),
forenoon (
ad meridiem), afternoon (
de meridie）
until 3 or 4, and evening (
suprema) from thence till sunset. After the
introduction of sundials and waterclocks, the day and night were divided each into twelve
hours; but the division was founded on the varying length of the day, so that each hour of
the day was longer, and conversely each hour of the night shorter, in summer than in winter.
It should be observed that several of the Eastern nations, for the purpose of preventing
confusion in their calculations with other nations, dropped the names of their months, and
merely counted the months, as the first, second, third, etc., month. For extended information
see Corsini,
Fast. Att., which, however, is very imperfect; Ideler,
Handbuch der mathem. u. technischen Chronol. (Berlin, 1826);
Clinton,
Fast. Hellen. vol. ii. Append. xix.; and more especially K. F.
Hermann,
Ueber griechische Monatskunde (Göttingen,
1844); Bergk,
Beiträge zur griechischen Monatskunde
(Giessen, 1845); Boeckh,
Ueber die vierjährigen Sonnenkreise
der Alten (Berlin, 1863); Mommsen,
Chronologie
(Leipzig, 1883); Ideler's work,
Lehrbuch der Chronologie, 2 vols.
(Berlin, 1826); Mommsen,
Die römische Chronologie
(Berlin, 1858); and Matzat,
Rö. Chronologie, 2 vols.
(Berlin, 1883). For further information connected with the ancient measurement
of time see the articles
Astronomia;
Dies;
Horologium;
Lustrum;
Nundinae;
Saeculum;
Vigiliae.
