The cycle of Jupiter now in general use is a cycle of sixty years, the saṁvatsaras of which bear certain special names, Prabhava, Vibhava, Śukla, Pramōda, &c., again in accordance with certain rules which we need not explain here. This cycle exists in three varieties.The 60-years cycle.
According to the original constitution of this cycle, the saṁvatsaras are determined as in the second or mean-sign variety of the 12-years cycle: each saṁvatsara commences when Jupiter enters a sign of the zodiac with reference to his mean motion and longitude; and it lasts for slightly more than 361.02 days. This variety is traced back in inscriptional records to A.D. 602, and is still used in Northern India.
Now, the saṁvatsaras are calculated by means of the astronomical solar year commencing with the Mēsha-saṁkrānti, the entrance of the sun into the sign Mēsha (Aries). The process gives the number of the saṁvatsara last expired before any particular Mēsha-saṁkrānti, with a remainder denoting the portion of the current saṁvatsara elapsed up to the same time; and the remainder, reduced to months, &c., gives the moment of the commencement of the current saṁvatsara, by reckoning back from the Mēsha-saṁkrānti. As the result, apparently, of unwillingness to take the trouble to work out the full details, at some time about A.D. 800 a practice arose, in some quarters, according to which that saṁvatsara of the 60-years cycle which was current at any particular Mēsha-saṁkrānti was taken as coinciding with the astronomical solar year beginning at that saṁkrānti, and with the Chaitrādi lunar year belonging to that same solar year. And this practice set up a lunisolar variety of the cycle, in connexion with which we have to notice the following point. While the duration of a mean-sign saṁvatsara is closely about 361.02 days, the length of the Hindu astronomical solar year is closely about 365.258 days. It consequently happens, after every 85 or 86 years, that a mean-sign saṁvatsara begins and ends between two successive Mēsha-saṁkrāntis. In the mean-sign cycle, such a saṁvatsara retains its existence unaffected; and the names Prabhava, Vibhava, &c., run on without any interruption. According to the lunisolar system, however, the position is different; the saṁvatsara beginning and ending between the two Mēsha-saṁkrāntis is expunged or suppressed, in the sense that its name is omitted and is replaced by the next name on the list. The second variety of the 60-years cycle, thus started, ran on alongside of the mean-sign variety, and, being eventually transferred, with that variety, to Northern India, is now known as the northern lunisolar variety. It preserves a connexion between the saṁvatsaras and the movements of Jupiter: but the connexion is an imperfect one; and both in this variety, and still more markedly in the remaining one still to be described, the saṁvatsaras practically became mere appellations for the solar and lunar years.
Meanwhile, just after A.D. 900, another development occurred, and there was started a third variety, which is now known as the southern lunisolar variety. The precise year in which this happened depends on the particular authority that we follow. If we take the elements adopted in the Sūrya-Siddhānta as the proper data for that time and for the locality—Western India below the Narbadā—to which the early history of the cycle belongs, the position was as follows. At the Mēsha-saṁkrānti in A.D. 908 there was current, by the mean-sign system, the saṁvatsara No. 2, Vibhava: but No. 4, Pramōda, was current by the same system at the Mēsha-saṁkrānti in A.D. 909; and No. 3, Śukla, began and ended between the two Mēsha-saṁkrāntis. Accordingly, No. 2, Vibhava, was the lunisolar saṁvatsara for the Mēshādi solar year and the Chaitrādi lunar year commencing in A.D. 908; and by the strict lunisolar system, which was adhered to by some people and is now known as the northern lunisolar system, it was followed in A.D. 909 by No. 4, Pramōda, the name of the intermediate saṁvatsara, No. 3, Śukla, being passed over. On the other hand, whether through oversight, or whatever the reason may have been, by other people the name of No. 3, Śukla, was not passed over, but that saṁvatsara was taken as the lunisolar saṁvatsara for the Mēshādi solar year and the Chaitrādi lunar year beginning in A.D. 909, and No. 4, Pramōda, followed it in A.D. 910. On subsequent similar occasions, also, there was, in the same quarters, no passing over of the name of any saṁvatsara. And this practice established itself in Southern India, to the exclusion there of the mean-sign and the northern lunisolar varieties; the discrepancy between the last-mentioned variety and the variety thus set up continuing, of course, to increase by one saṁvatsara after every 85 or 86 years. In this variety, the southern lunisolar variety, all connexion between the saṁvatsaras and the movements of Jupiter has now been lost.
The present position of the 60-years cycle in its three varieties may be illustrated thus. In Northern India, by the mean-sign system the saṁvatsara No. 46, Paridhāvin, began, according to different authorities, in August, September or October, A.D. 1899. Consequently, by the northern or expunging lunisolar system, that same saṁvatsara, No. 46, Paridhāvin, coincided with the Mēshādi civil solar year beginning with or just after 12th April, and with the Chaitrādi lunar year beginning with 31st March, A.D. 1900. But by the southern or non-expunging lunisolar system those same solar and lunar years were No. 34, Śarvarin.
The treatment of the cycles of Jupiter in the Sanskrit books shows that it was primarily from the astrological point of view that they appealed to the Hindus; it was only as a secondary consideration that they acquired anything of a chronological nature. For the practical application of any of them to historical purposes, it is, of course, necessary that, along with the mention of a saṁvatsara, there should always be given the year of some known era, or some other specific guide to the exact period to which that saṁvatsara is to be referred. But it is fortunately the case that the saṁvatsaras have been but rarely cited in the inscriptional records without such a guide, of some kind or another.
The Saptarshi reckoning is used in Kashmīr, and in the Kāṇgra district and some of the Hill states on the south-east of Kashmir; some nine centuries ago it was also in use in the Punjab, and apparently in Sind. In addition to being cited by such expressions as Saptarshi-saṁvat, “the year (so-and-so) The Saptarshi reckoning. of the Saptarshis,” and Śāstra-saṁvatsara, “the year (so-and-so) of the scriptures,” it is found mentioned as Lōkakāla, “the time or era of the people,” and by other terms which mark it as a vulgar reckoning. And it appears that modern popular names for it are Pahāṛī-saṁvat and Kachchā-saṁvat, which we may render by “the Hill era” and “the crude era.” The years of this reckoning are lunar, Chaitrādi; and the months are pūrṇimānta (ending with the full-moon). As matters stand now, the reckoning has a theoretical initial point in 3077 B.C.; and the year 4976, more usually called simply 76, began in A.D. 1900; but there are some indications that the initial point was originally placed one year earlier.
The idea at the bottom of this reckoning is a belief that the Saptarshis, “the Seven Rishis or Saints,” Marīchi and others, were translated to heaven, and became the stars of the constellation Ursa Major, in 3076 B.C. (or 3077); and that these stars possess an independent movement of their own, which, referred to the ecliptic, carries them round at the rate of 100 years for each nakshatra or twenty-seventh division of the circle. Theoretically, therefore, the Saptarshi reckoning consists of cycles of 2700 years; and the numbering of the years should run from 1 to 2700, and then commence afresh. In practice, however, it has been treated quite differently. According to the general custom, which has distinctly prevailed in Kashmīr from the earliest use of the reckoning for chronological purposes, and is illustrated by Kalhaṇa in his history of Kashmīr, the Rājataraṁgiṇī, written in A.D. 1148–1150, the numeration of the years has been centennial; whenever a century has been completed, the numbering has not run on 101, 102, 103, &c., but has begun again with 1, 2, 3, &c. Almanacs, indeed, show both the figures of the century and the full figures of the entire reckoning, which is treated as running from 3076 B.C., not from 376 B.C. as the commencement of a new cycle, the second; thus, an almanac for the year beginning in A.D. 1793 describes that year as “the year 4869 according to the course of the Seven Ṛishis, and similarly the year 69.” And elsewhere sometimes the full. figures are found, sometimes the abbreviated ones; thus, while a manuscript written in A.D. 1648 is dated in “the year 24” (for 4724), another, written in A.D. 1224 is dated in “the year 4300.” But, as in the Rājataraṁgiṇī, so also in inscriptions, which range from A.D. 1204 onwards, only the abbreviated figures have hitherto been found. Essentially, therefore, the Saptarshi reckoning is a centennial reckoning, by suppressed or omitted hundreds, with its earlier centuries commencing in 3076, 2976 B.C., and so on, and its later centuries commencing in A.D. 25, 125, 225, &c.; on precisely the same lines with those according to which we may use, e.g. 98 to mean A.D. 1798, and 57 to mean A.D. 1857, and 9 to mean A.D. 1909. And the practical difficulties attending the use of such a system for chronological purposes are obvious; isolated dates recorded in such a fashion cannot be allocated without some explicit clue to
