Book of Indian Eras, with Tables for Calculating Indian Dates c13.30

c13.30

To remedy this defect Meton proposed in B.C. 432 his famous cycle of 19 solar years of 365¼ days each, which differs by only a small fraction from 235 lunations. Meton's value of the 19 solar years as 6940 days was a little in excess of the truth, as a year of 365¼ days gives only 6939·75 days in 19 years. As this excess of ¼ day amounted to a whole day in 76 years, Kallippus, in B.C. 330, introduced the cycle of 76 years, or four Metonic periods, from which he retrenched the extra day. But beyond this, according to Clinton, "he appears to have made no change in the ἐννεα-και-δεκαετηρις of Meton." It is supposed, from the account of Timocharis of the 36th and 47th years being anni communes, that he closed the 6th Metonic cycle at its 8th year, or B.C. 330, which, accordingly, became an annus communis as the 1st of the Kallippic cycle of 76 years, which could not have happened if the original Metonic cycle had not been interrupted. But Clinton quotes a marble which renders this arrangement doubtful. It is quite certain that it could not have been adopted in Syria, as we know that the year 148 of the Seleukidan era, or B.C. 165-64, was intercalary,* which is true of the Metonic cycle, but disagrees with that of Kallippus. As the Parthian coin of Vologases III shows the same accordance with the Metonic reckoning, there can be no doubt that the Kallippic correction had not been introduced into either Syria or Parthia. Clinton also deduces from "the three years described by Ptolemy as 67, 75, and 82 of the Chaldæans, commencing respectively October 15, October 16, and October 1, that the Macedonians must have received the cycle in the 9th year of a Metonic ἐννεα-και-δεκαετηρὶς, which would be the second of a Kallippic. For this reason I have adopted the Metonic cycle in the accompanying tables, which show the initial day of every year down to the close of the Parthian empire. I have numbered the Metonic cycles I, II, III, IV, &c., and should it be required to convert any date into the Kallippic reckoning, it is only necessary to throw back every date in each period of 76 years by one day; or, as the Kallippic correction was established in B.C. 330, to antedate by one day every initial day in the Metonic Cycles IV, V, VI VII; by two days those of Cycles VIII, IX, X, XI; by three days those of Cycles XII, XIII, XIV, XV; and so on, deducting one more day for every four Metonic cycles.