CALENDAR

A distribution or division of time into periods adapted to the purposes of civil life; also a table or register of such divisions, exhibiting the order in which Ihe seasons, months, festivals, and holidays succeed each other during the year. The word is derived from the ancient Latin verb calare, to call. In the early ages of Rome, it was the custom for the pontiff's to call the people together on the first day of <;ach month, to apprise them of the days that were to be kept sacred in the course of it. Hence dies calendce, the calends or first days of the different months. The calendars in use throughout Europe are borrowed from that of the Romans. Romulus is supposed to have first undertaken to divide the year in such a manner that certain epochs should return periodically after a revoCALENDAR. lution of the sun; but the knowledge of astronomy wa« not then sufficiently advanced to allow this to be 'done with much precision. He placed the commencement of the year in spring, and divided it into 10 months — March, April, May, June, Quintilis, Sextilis, September, October, November, and December. March, May, Quintilis, and October contained thirty-one days eacli; the other six contained only thirty. The names Quin tills and Sextilis remained in the calendar till the end of the republic, when they were changed into July and August; the former in flattery of Julius Ciesar, and the latter of August us. The year of Romulus contained onlj;304 days. Numa added two months; January to tlie beginning of the year, and February to the end. About the year 452 b. c. this arrangement was changed by the Decemvirs, who placed February after January; since that time the order of the months has remained undisturbed. In Numa's )'ear the months consisted of 29 and 30 days alternately, to correspond with the synodic revolution of the moon. The year would therefore consist of 354 daj's; but one day was added to make the number odd, as being more lucky. In order to produce a correspondence with the solar year, Numa ordered an intercalary month to be inserted every second year between the 23rd and 24th of February, consisting alternately of 22 and 23 days. Had this regulation been strictly adfiered to, the mean length of the year would have" been 3G5i days, and the months would have continued for a long time to correspond with the same seasons. But a discretionary power over the intercalary month was exercised by the pontiffs, who frequently abused it for the purpose of hastening or retarding the days of the election of magistrates; and the Roman calendar continued in a state of uncertainty and confusion till the time of Julius Caesar, when the civil equinox differed from the astronomical by three months. Under the advice of the astronomer Sosigenes, Ca;sar abolished the lunar year, and regulated the civil year entirely by the sun. He decreed that the common year should consist of 3G5 days; but that every fourth year should contain 366. In distributing the days among the different months, he ordered that the odd months, that is, the first, third, fifth, seventh, ninth, and eleventh, should contain each 31 days, and the other months 30; excepting February, which in common years was to contain only 29 days, but every fourth year 30 daj's. This natural and convenient arrangement was interrupted to gratify the frivolous vanity of August us, by giving August, the month named after him, an equal number of days wit« July, which was named after the first Caesar. The intercalary day, which occurred every fourth year, was inserted between the 24th and 25th of February. According to the peculiar and awkward manner of reckoning adopted by the Romans, the 24th of February was called the sixth before the calends of March, sexto calendas. In the intercalary year this day was repeated, and called bis -sexto calendas; whence the term bi extile. The corresponding, English term, leap year, appears le correct, as it seems to imply that a day was leapt over instead of being thrust in. It may be remarked, that in the ecclesiastical calendar the intercalary day is still inserted between the 24th and 25th of February. The Julian year consisted of 365i days, and consequently differed in exce by 11 minutes 10"35 sec. from the true solar year, which consists of 365 d. 5 h. 48 m. 49-62 sec. In consequence of this difference the astronomical equinox, in the course of a few centuries, sensibly fell back towards the beginning of the year. In the time of Julius Caesar it corresponded to the 25th of March; in the sixteenth century it had retrograded to the Uth. The correction of this error was one of the purposes sought to be obtained by the reformation of the calendar effected by Pope Gregory XIII. in 1582. By suppre ing 10 days in the calendar, Gregory restored the equinox to the 21st of March, the day on which it fell at the time of the Council of Nice in 325; the place of Easter and the other moveable church feasts in the ecclesiastical calendar having been prescribed at that council. And in order that the same inconvenience might be prevented in future, he ordered the intercalation which took place every fourth year to be omitted in years ending centuries; that is to sayii on the iOOth, 200th, .; excepting on the 400th, and the years which are multiples of 400. The Greg or i an rule of intercalation may therefore be ex. pre ed as follows: — " Every year of which the number is divisible by 4 without a remainder is a leap year, excepting the centesimaKyears, which are only leap years when divisible by 4 after suppre ing the two zeros." Thus 1600 was a leap year; 1700 and 1800 were common years; 1900 will be a common year, 2000 a leap year, and so on. The Greg or i an method of intercalation thus gives 97 intercalations in 400 vears; consequently 400 years contain 400 x 365+97 = 14'6097 days, and therefore the length of one year is 365-2425 days, or 365 d. 5h. 49m. 12 sec, which exceeds the true solar year by 22-38 sec, an error which amounts only to one day in 3866 years. [s. 193]