The eight-year cycle (tahōn thōn) is the system by which the Achehnese compute the calendar of the Mohammedan lunar year. It is described by C. Snouck Hurgronje in the chapter on Achehnese calendars, festivals and seasons, and was used in Acheh “from the earliest times” as the method of fixing the beginnings of the months, in preference to the ruʽyah or observation of the new moon enjoined by the Shafiʽite law. Although all the Mohammedans of the Archipelago are Shafiʽites, “the doctrine of the ruyah is far from being universally observed. In many districts calculation (hisāb) is adhered to, though according to the teaching of that school it should only be employed for the indifferent affairs of daily life. It is only lately under the influence of Mecca and Hadramaut that the ruyah has been more universally accepted.”
In Acheh, the “calculation” was the method followed from the earliest times. The ulamas overcame the difficulty of a conflicting doctrine in the books of the law by the consideration “that in these parts the atmosphere is only occasionally clear enough to allow of the new moon being seen on the first day of her appearance.” In the edicts of the sultans there is a regulation directing “that the commencement of the fasting month in each year should be fixed by a council of the learned held on the last Friday of the preceding month. The date was then made known to the people by the firing of guns on the previous day. This was quite inadmissible according to the ruyah doctrine.” There are in Acheh a few ulamas who are acquainted with some of the principles of Arabic astronomy (that of the middle ages), which they use as the basis of their calculations, but as a rule reference is only made to certain tables given in Malay books, without any regard to the way in which these tables were arrived at, or the necessity for correction of the errors in reckoning to which they give rise after some lapse of time.
The system is as follows. The years are first divided into groups of eight, and each of these eight years has its proper Arabic letter (tahōn thōn), the numerical value of which is the cypher of that year. As the order of sequence of the 8 year-letters is invariable, one need only know the letter of the preceding year to arrive at that of the current year; and even without this the letter may be calculated from the year of the Hijrah. The twelve months have each their letter in like manner, and the numerical value of that letter is the cypher of its month. If we add the cypher of a given year to that of a certain month, the sum of the two gives “the clue to the day of the week which is the first day of that month in the year in question.” To apply this clue, one starts with the day of the week with which the cycle or series of years begins. Since this day recedes one place in every 120 years according to a necessary adjustment in the system, there are seven different ways of counting, called after the days of the week which respectively begin the cycles: Aḥadiyyah, Ithnainiyyah, Thalathiyyah, Arbaʽiyyah, Khamsiyyah, Jumʽiyyah, Sabtiyyah. The cycles beginning with Wednesday or Thursday are now usually employed in different parts of the Archipelago; in Acheh the Arbaʽiyyah (Wednesday) method is that most in use.
The cycle of 8 years, in the Achehnese form, runs as follows: (1) Alèh (ا), numerical value 1; (2) Hè (ه), value 5; (3) Jim (ج), value 3; (4) Zòè (ز), value 7; (5) Dāy away (د), value 4; (6) Ba (ب), value 2; (7) Waw (و), value 6; (8) Dāy akhè (ض), value 4. The calculation for finding the letter of a Hijrah year consists in dividing the number representing the year by 8 and counting off the year-letters in the above order, beginning with Waw, to the number of the remainder. Thus the year 1309 divided by 8 leaves 5; counting from Waw 5 places onwards, we reach Jim; Jim is thus the letter of that year. To fix the year-letters on the memory they are formed into a single word with the help of vowels, thus: ahjizdabuda (اهجوزدبوض). The Achehnese cycle has this in common with the eight-year cycle of the Javanese (as to which see Dr. A. B. Cohen Stuart’s remarks in the Government Almanac for 1868) that its year alip if divided by 8 leaves a remainder of 3; the year-letters, on the other hand, are different, the Achehnese corresponding with those found in some Arabic handbooks which Newbold cursorily refers to as in use among the Malays, and which Dr. Cohen Stuart met with in a Sumatran almanac.
See Also
- Keunong
- Puasa (Ramadhan fasting month)
- Dr. A. B. Cohen Stuart
- T. J. Newbold
- Asan-Usen
- Friday service (Jum’at)
Source
The Achehnese, Vol. I, by Dr. C. Snouck Hurgronje, translated by A.W.S. O’Sullivan, indexed by R.J. Wilkinson. Leyden: E.J. Brill, 1906.