Calendar

Calendar (from Calends), the mode of adjusting the natural divisions of time with respect to each other for the purposes of civil life. For the measurement of time, as for the measurement of any other magnitude, some standard must be adopted. The earliest standard interval was the day, marked out by the alternation of light and darkness, and determined by the rotation of the earth on its axis. For longer periods, the lunar month, from new moon to new moon, an interval of about $29\backslash frac\{1\}\{2\}$ days, was the standard next fixed upon; and finally the recurrence of the seasons suggested the year. The duration of the year was determined in various ways by the nations of antiquity, one of the earliest ways being to make it include a certain number of lunar months. Twelve lunar months, giving a year of 354 days, were taken as a near approach to a course of the seasons. In process of time, however, it was discovered that with this rough approximation to the true value of a year the seasons did not correspond to the same months, and it was necessary, in order to prevent them gradually making the round of the whole year, to make some adjustment. For this purpose the Jews and the Greeks employed much the same expedients; they intercalated a month from time to time, the former 7 times in a cycle of 19 years, the latter 3 times in a cycle of 8. The Romans are said, and the statement is confirmed by what is known of their sacred rites and customs, to have had originally a year of 10 months, beginning with March and ending with December, which means 'tenth' period. Early in their history, however, they adopted, from their belief in the luck attendant on odd numbers, a lunar year of 355 days, and added two new months, January and February. But, like the Greeks, they were compelled, in order to accommodate their lunar year to the solar year, to make occasional intercalations. The making of these intercalations was in the hands of the pontiffs, who had sole charge of the calendar, and they used this power unscrupulously for the gratification of their friends or the annoyance of their enemies. They lengthened or curtailed the year, often in order that a magistrate or farmer of the taxes might enjoy a longer or shorter lease of office than was permitted by law, and without regard to the unsetting of the seasons, and at the time when Julius Cæsar became dictator, the spring festivals occurred in the nominally summer months. To clear away all this confusion, Cæsar, with the help of Sosigenes, an Alexandrian astronomer, undertook a thorough reform of the calendar. He effected it by making the year now called 46 B.C., 'the year of confusion,' consist of 445 days, and the succeeding years of 365 days, with the exception of every fourth year, which was to consist of 366. This method of adjusting the days to the year is called the Julian calendar. The number of days in the months from January to December before Cæsar's time had been respectively 29, 28, 31, 29, 31, 29, 31, 29, 29, 31, 29, 29. These numbers Cæsar changed to 31 and 30 alternately, with the exception of February, which was to have 29 in ordinary years and 30 in leap-years. In honour of himself he also changed to July the name of the month which followed June. In the application of the Julian correction to the calendar the pontiffs again went wrong, by inserting the leap-years once in every three instead of every four years. This mistake of theirs continued till the year now called 8 B.C., when three leap years too many had been reckoned, and Augustus ordained that there should be no leap-year for 12 years, which, according to the Roman way of counting, would make leap-year occur in 4 A.D. At the same time Augustus gave his own name to the month following July, added one day to it which he took away from February, and that there might not be three consecutive months of 31 days each, he made September, October, November, December consist of 30, 31, 30, 31 days, instead of 31, 30, 31, 30.

The Julian calendar assumes the length of the solar year to be $365\backslash frac\{1\}\{4\}$ days, whereas it is 11 minutes and a few seconds less. This annual error, a small one doubtless, accumulated as years rolled on, and began to be fully recognised about the beginning of the 16th century. Some proposals, such as that of Stöffler in 1518 and of Pitatus of Verona in 1537, were made to rectify the error, but the matter was not taken up in earnest till 1577, by Pope Gregory XIII. As in 1582 the vernal equinox occurred at a date (11th March) 10 days earlier than it did at the time of the Council of Nice in 325 A.D., Gregory published a bull, dated 1st March 1582, annulling 10 days, so that what would have been reckoned the 5th October 1582 was to be reckoned the 15th October. In order also that the displacement might not recur, it was further ordained that three of the leap-years which occur in 400 years should be considered common years. The three leap-years selected to be reduced to common years were those which close the centuries (i.e. which end with 00) and are not divisible by 400. Thus, 1600 was leap-year, 1700 and 1800 were common years, 1900 will be a common year, 2000 will be leap-year, and so on. This method of adjusting the days to the year is called the Gregorian calendar, or the new style. The new style was adopted exactly according to the mandate of the pope in Spain, Portugal, and part of Italy; in France and some of the provinces of the Low Countries it was adopted in the same year by calling the 10th of December the 20th, and the 15th of December the 25th; and by continental Catholics generally before the end of the 16th century. Scotland adopted the modern New Year's Day in 1600. Most Protestants, however, were then too much inflamed against Catholicism in all its relations to receive even a purely scientific improvement from such hands, and it was more than a century before they abandoned the old style. In England a bill to this effect was brought before parliament in 1585, but did not get beyond a second reading in the House of Lords; and it was not till 1751 that an act was passed (24 Geo. II.) 'for regulating the commencement of the year, and for correcting the calendar now in use.' It was then enacted that 11 days should be omitted after the 2d of September 1752, so that the ensuing day should be the 14th. The enactment was not carried out without provoking discontent among uneducated people, many of whom imagined that they were defrauded of the omitted days, and assailed unpopular statesmen with the cry, 'Give us back our 11 days.' The reason for the omission of the additional day is that according to the old style 1600 and 1700 were both considered leap-years; according to the new style 1700 was a common year. At present, since 1800 was a leap-year according to old style, and a common year according to new style, there is a difference of 12 days between the styles. Russia, Greece, and the smaller states, such as Servia, belonging to the Greek Church, are now the only countries which still adhere to the old style. The same act which introduced the new reckoning in 1752 shortened by nearly three months the year 1751. For it had been the practice to commence the year with the 25th of March, the Feast of the Annunciation, and the year 1751 so commenced, but the year 1752 and all subsequent years began with the 1st of January. In the national accounts of the United Kingdom, the financial year ends 31st March, and thus closely corresponds still with the old practice.

In 1793 the National Convention of the first French republic decreed that the common era should be abolished in all civil affairs, and that a new era should commence from the foundation of the republic, 22d September 1792. The year was to be divided into 12 months of 30 days each, with 5 complementary days at the end, which were to be celebrated as festivals, and were dedicated to Virtue, Genius, Labour, Opinion, Rewards. Every fourth or 'Olympic' year was to have a sixth complementary day to be called 'revolution day,' and every period of four years was to be called a Franciade. The first, second, and third centurial years—viz. 100, 200, 300 were to be common years, the fourth centurial year 400 was to be a leap-year, and this was to continue till the fortieth centurial year 4000, which was to be a common year. The months were to be divided into three parts of 10 days each, called decades. The names of the months and the days of the Gregorian calendar to which they corresponded were as follows :

By Napoleon's command this new system was abolished, and the use of the Gregorian calendar resumed on January 1, 1806.

In the Jewish calendar, whose reckoning counts the years downwards from the Creation, the year is luni-solar and may be ordinary or embolismic. An ordinary year has 12 months (354 days), an embolismic year 13 months (384 days). The names of the months are Tisri, Hesvan, Kislef, Tebet, Sebat, Adar (with Veazar in embolismic years), Nisan, Yiar, Sivan, Tamuz, Ab, Elul; the New Year (1st Tisri), which falls between 5th September and 5th October, fell in the Jewish year 5649 on 6th September 1888.—For the Mohammedan calendar, see HEGIRA. Other information as to differences in the method of time-reckoning will be found at CHRONOLOGY. The Ecclesiastical calendar will be treated at EASTER, SAINTS, and other articles; for the Positivist calendar, see POSITIVISM; see also MONTH, YEAR.