Datum

“ The days are distributed in the calendar into cycles of sixty, in the same manner as ours are distributed into weeks, or cycles of seven. Each day of the cycle has a particular name, and as it is a usual practice, in mentioning dates, to give the name of the day along with that of the moon and the year, this arrangement affords great facilities in verifying the epochs of Chinese chronology. The order of the days in the cycle is never interrupted by any intercalation that may be necessary for adjusting the months or years. ”

“ The counting that is important for the calendar is that according to the days of the lunar month, but in this the primitive peoples hold to the concrete phenomenon of the moon. The habit of reckoning in this fashion may however be partly responsible for the fact that among certain peoples [323] every day of the month has not been given a name, but the days are counted from certain points of departure, such as new moon, full moon, etc. Very rarely do we meet with a genuinely calendrical use of the tally. ”

“ The rapid progress of astronomy led to the consideration of this subject, and many new calendars were proposed. [ [ [Author:Ugo Boncompagni|Pope Gregory XIII.] ] convoked a large number of mathematicians, astronomers, and prelates, who decided upon the adoption of the calendar proposed by the Jesuit Lilius Clavius. To rectify the errors of the Julian calendar it was agreed to write in the new calendar the 15th of October immediately after the 4th of October of the year 1582. The Gregorian calendar met with a great deal of opposition both among scientists and among Protestants. ”

“ Initial-series dating; (2) Secondary-series dating; (3) Calendar-round dating; (4) Period-ending dating; (5) Katun-ending dating, or the u kahlay katunob. While apparently differing considerably from one another, in reality all are expressions of the same fundamental idea, the combination of the numbers 13 and 20 (that is, 260) with the solar year conceived as containing 365 days, and all were recorded by the same vigesimal system of numeration; that is:
1. All used precisely the same dates, the 18,980 dates of the Calendar Round;
2. All may be reduced to the same fundamental unit, the day ”

“ When dates have been taken from computations of time other than the Christian era, it should be understood that the corresponding day has been made to conform to our own era, and consequently perfect accuracy can not be claimed for them. ”

“ After the Julian calendar had been used several centuries, the improved state of astronomy disclosed the fact that computed time did not keep pace with actual time, because the year did not consist of three hundred and sixty-five days and six hours but was about eleven minutes ten seconds less. Hence, by inserting an extra day for leap year, we gain upon true time forty-four minutes, forty seconds, which makes an error of a day in about one hundred and thirty-one years ”

“ In countries, however, where continued clearness of the sky was not afforded, or where the necessity was urgently felt for a regular determination of future dates, the seers at length desired that they be permitted to calculate, upon the basis of the past determinations of the duration of the regular months, the recurrence of the phases of the moon for a certain time in advance, and therewith the regular succession of the months, and to publicly record the number and the method of counting the days of the single months. ”

“ For the fourteenth day of Clavius is generally the fifteenth day of the mean moon of the heavens, and therefore most often that of the real moon. But for this, 1818 and 1845 would not have been the only instances of our day in which the English precept would have contradicted the Calendar.
11. In the construction of the Calendar, Clavius adopted the ancient cycle of 532 years, but, we may say, without ever allowing it to run out. At certain periods, a shift is made from one part of the cycle into another. ”

“ POPULAR MONTHS OF THE EUROPEAN PEOPLES. In ancient times, and even at the present day in lands which lie outside the path of the great leveller, civilisation, the months taken over with the Roman calendar are not numbered divisions of the year, the names of which are a matter of indifference, but are concretely conceived and named as seasons. They are, in fact, nothing but seasons, the number and duration of which are determined by the conventional calendar. ”

“ The Saros of the Chaldaeans, the Olympiad of the Greeks, and the Roman Indiction are instances of this mode of reckoning time. Several cycles were formerly known in Europe; but most of them were invented for the purpose of adjusting the solar and lunar divisions of time, and were rather employed in the regulation of the calendar than as chronological eras. They are frequently, however, of very great use in fixing dates that have been otherwise imperfectly expressed, and consequently form important elements of chronology. (W. L. R. C.)
Modern Results of Archaeological Research. ”

“ The Golden Numbers were introduced into the calendar about the year 530, but disposed as they would have been if they had been inserted at the time of the council of Nicaea. The cycle is supposed to commence with the year in which the new moon falls on the 1st of January, which took place the year preceding the commencement of our era. Hence, to find the Golden Number N, for any year x, we have N = x+1/19r , which gives the following rule: Add 1 to the date, divide the sum by 19; the quotient is the number of cycles elapsed, and the remainder is the Golden Number. ”

“ Year—If the civil year correspond with the solar the seasons of the year will always come at the same period. But if the civil year is supposed to be too long (as is the case in the Julian year) the seasons will go back proportionately; but if too short they will advance in the same proportion. Now, as the ancient Egyptians reckoned thirty days to the month invariably, and to complete the year, added five days, called supplementary days, their year consisted of 365 days. ”

“ These documents are all dated in such and such a month of such and such a year of some king’s reign; the months are the same (at first under their earlier Accadian names [3] ) as those we [5] find in the almanacs translated by Epping and Strassmaier, and we meet in them, and in other historical inscriptions, with the intercalary months, the second Elul, and the second Adar. It would seem, then, that it was the same calendar, worked in the same way, that held its place through these two thousand years. ”

“ He called it the Gregorian Calendar; but there are lots of other calendars besides—there's the Jewish and Mohammedan, and a variety of calendars in the East. All of them can't be right. The result is that none of them are right, and the world is in confusion. Some calendars mark off too many days, others mark off too few. Half the world is ahead of Time, and the other half behind it. ”

“ In consequence of the solar and lunar equations, it is evident that the epact, or moon's age at the beginning of the year, must, in the course of centuries, have all different values from one to thirty inclusive, corresponding to the days in a full lunar month. Hence, for the construction of a perpetual calendar, there must be thirty different sets or lines of epacts. ”

“ The cycle being interrupted by the Gregorian rule of intercalation, causes all events which occur between 28 and 12 years of the close of the centuries to fall on the same day of the week again in 40 years; and those events that fall within 12 years of the close of these centuries, to fall on the same day of the week again in 12 years ”

“ By the new calendar the year of 365 days was divided into twelve months of thirty days each, every month being divided into three periods of ten days, each of which were called décades, and the tenth, or last, day of each decade being a day of rest. ”

“ If the interpretation of the text be correct, calculation would fix the date between the year 3,007 and 3,010 of the ancient era, or a thousand years after the epoch attributed to the reign of Menkera in Mariette's chronological table. In any case, it is to be hoped that future discoveries will enable us with certainty to trace back the course of ages, and to determine positive dates for the origins of history, with which may be connected the fluctuating chronology of the most remote events of which the human race has preserved the memory. ”

“ A civil, or legal, day ends at the instant of 24 o'clock, midnight, and the next day commences. The time is continuous, the last instant of a day touching the first instant of the next. This is true for all parts of the earth; but something in addition to this happens at a certain meridian called the “date line.” Refer again to Fig. 47 which is drawn with 24 meridians representing hours. As we are taking Greenwich for our time, the meridians are numbered from 0°, on which the observatory of Greenwich stands. ”

“ Though confounded with calendar, it is essentially different—the latter relating to time in general, and the almanac to that of a year; but the term calendar can be properly used for a particular year. (See Ephemeris.)
ALMATH [Hamal] . The star in Aries whence the first mansion of the moon takes its name. ”

“ The Roman calendar was in early times even more confused than the Greek. There appears to have been at one time a year of either 304 or 354 days; tradition assigned to Numa the introduction of a cycle of four years, which brought the calendar into fair agreement with the sun, but made the average length of the month considerably too short. Instead, however, of introducing further refinements the Romans cut the knot by entrusting to the ecclesiastical authorities the adjustment of the calendar from time to time, so as to make it agree with the sun and moon. ”

“ The same is the case with the knowledge of the revolutions of the spheres, of which the yearly calendar is but one fruit. The excellence of the calculation of the calendar is famous, and it is well known what deep root it has taken among these people, few in number, yet excellently equipped with model institutions. Could it be otherwise? On account of the smallness, humbleness, and dispersion of the people it is hardly noticed among the other nations, yet those relics of the Divine made it into one firmly established organization. ”

“ Their value for historical research depends upon their age, and also upon our knowledge of the locality for which they were drawn up, the best data for discovering this latter point being afforded by the names of local saints contained in the calendar itself. No calendar can be set aside as altogether useless, for in case of need all can throw light upon the history of at least their own locality. ”

“ One historian, indeed, assures us that they threw their years into cycles of ten, a hundred, and a thousand years, and that by these cycles they regulated their chronology.15 But this assertion—not improbable in itself—rests on a writer but little gifted with the spirit of criticism, and is counter-balanced by the silence of every higher and earlier authority, as well as by the absence of any monument, like those found among other American nations, to attest the existence of such a calendar. ”

“ The only calendar we men have is a calendar of dates, fitted to the movements of the sun and moon. God has a calendar, too, but it is a calendar of events, not of dates. The completion of His plans doesn't depend on so many revolutions of the earth about the sun, but on the faithful revolution of His followers in their movement around the earth telling men of Jesus. ”

“ A clock of the second type yields what is called a relative date, placing an event as before or after another event, but does not tell us exactly how far they are apart in time nor how long ago they occurred. ”

“ For altho’ this Horologe has no certain Hours or Time pre-assigned to it; yet it hath nevertheless, greater or lesser Numbers Æquated to the Variableness of Motion or Time, (viz.) If fitted to be used here in England, then it hath (or may have) one sort of Numbers (or Time) for finding the Hour and Minute, in the Summer Season; another for Winter; and a third for the Spring and Fall; one when it lyeth undisturbed in one and the same place; another (if you please) when carry’d always in a Rattling Coach. ”

“ The mother counts by weeks—very good—the squire by the proper calendar. One makes the child three months and two weeks, and she is right; the other deducts eleven days to fit the calendar, and he, too, is right.”
“Out with it,” cried Caleb; “out with such a calendar! Why, the whole realm will be in confusion. None of us will ever know how old we are, or when the church-days are due; but I doubt if, in spite of it all, the Pope’s new calendar doesn’t keep the squire’s rent-day straight. They’ll look out for that.” ”

“ We will next proceed on the supposition that these indicate the months. In that case the dates given in the present example will be 9 Oc, 9 Ik, 9 Ix, 9 Cimi, and 9 Ezanab of the 15th month (Muan) . In this the feast, religious ceremony, or whatever the date refers to, occurs always in the same month, and so far agrees with what is left on record in reference to religious ceremonies and observances. As only the day and month are given, it is possible, as heretofore stated, to find four dates to each day. ”

“ CALENDAR REGULATION. 1. THE INTERCALATION. The circumstance that the lunar months are among almost all peoples named from the phases of Nature involves the necessity of an agreement between the two really incommensurable periods given by the sun and the moon. This problem is the central point of the older scientific chronology. We shall now investigate more closely how the problem has arisen, and what has been its development among the primitive peoples.
Where there is only a series of less than twelve months, the problem of calendar regulation does not exist. ”