Page:Christiaan Snouck Hurgronje - The Achehnese - tr. Arthur Warren Swete O'Sullivan (1906).djvu/288

 keunòng series. These periods can be distinguished by the numerals of their lunar dates and each of them constantly falls in the same season of the year.

To every lunar year there are almost precisely 13 keunòngs. Thus by neglecting the invisible one, which would properly be called 28, 29 or 30, and which falls in the great interval between keunòngs 1 and 23, we get exactly one keunòng for each lunar month. This makes the calculation extremely easy, but it is obvious that as we advance we shall in time arrive at a month in which the keunòng we obtain by observation falls on a different date from that which the series would lead us to expect. It is in fact at the end not of a lunar, but a solar year, that the keunòngs revert to nearly the same interval of time separating them from the preceding new moon. By continually counting off the Achehnese keunòng series with the months of the lunar year, we neglect the difference between the average number of keunòngs contained in a solar year (13.363) and the number contained in a lunar year (13 exactly). Thus about once in three years,—as often in fact as the keunòng phenomenon exhibits itself 14 times in a solar year, we must count one keunòng more than usual so as not to come into conflict with the calendar of the solar year which we find written on the heavens in terms of keunòngs.

This necessary correction is made by the Achehnese in a purely empirical manner, for they have, at present at least, no proper basis of calculation whatever,—indeed they do not even understand the real meaning of the keunòng-calculation. They notice of course at certain times, that the keunòngs of their series move faster than the real ones. As the observed sequence also fails in other respects to correspond exactly with the principles on which their series is based, they can fix no stated time at which the divergence of the two becomes excessive and calls for correction; one observes it earlier, another later.