Page:Sewell Dikshit The Indian Calendar (1896) proc.djvu/80

Madras, is a method for obtaining approximate results without any calculation by the careful use of mere eye-tables, viz., Tables XIV. and XV. These, with the proper use of Table I., are alone necessary. But it must never be forgotten that this result may differ by one, or at the utmost two, days from the true one, and that it is not safe to trust to them unless the era and bases of calculation of the given date are clearly known. (See Art. 126 below.)

124. By our second method B (Arts. 137, 138), which follows the system established by Mr. W. S. Kṛishṇasvâmi Naidu of Madras, author of "South Indian Chronological Tables"

(Madras 1889), and which is intended to enable an approximation to be made by a very simple calculation, a generally accurate correspondence of dates can be obtained by the use of Tables I., III., and IX. The calculation is so easy that it can be done in the head after a little practice. It is liable to precisely the same inaccuracies as method A, neither more nor less.

125. Tables II. and III. will also be sometimes required for both these methods.

126. The result obtained by either of these methods will thus be correct to within one or two days, and as often as not will be found to be quite correct; but there must always be an element of uncertainty connected with their use. If, however, the era and original bases of calculation of the given date are certainly known, the result arrived at from the use of these eye-Tables may be corrected by the week-day if that has been stated; since the day of the month and year will not be wrong by more than a day, or two at the most, and the day of the week will determine the corresponding civil day. Suppose, for instance, that the given Hindu date is Wednesday, Vaiśâkha śukla 5th, and it is found by method A or method B that the corresponding day according to European reckoning fell on a Thursday, it may be assumed, presuming that all other calculations for the year and month have been correctly made, that the civil date A.D. corresponding to the Wednesday is the real equivalent of Vaiśâkha śukla 5th. But these rough methods should never be trusted to in important cases. For a specimen of a date where the bases of calculation are not known see example xxv., Art. 160 below.

127. When Tables XIV. and XV. are once understood (and they are perfectly simple) it will probably be found advisable to use method A in preference to method B.

128. As already stated, our method "C" enables the conversion of dates to be made with precise accuracy; the exact moments of the beginning and ending of every tithi can be ascertained; and the corresponding date is obtained, simultaneously with the week-day, in the required reckoning.

129. The weekday for any European date can be found independently by Table XIII.. which was supplied by Dr. Burgess.

131^[1] (5) To find the karaṇa, nakshatra, or yoga current on any Indian or European date; and to verify any Indian date.

Method C includes calculations for the karaṇa, nakshatra and yoga current at any given moment of any given day, as well as the instants of their beginnings and endings; but for this purpose, if the given date is other than a tithi or a European date, it must be first turned into one or the other according to our rules (Art. 139 to 152.)

132. It is impossible, of course, to verify any tithi or solar date unless the week-day, nakshatra. karaṇa, or yoga, or more than one of these, is also given; but when this requirement is satisfied our method C will afford proof as to the correctness of the date. To verify a solar date it must first be turned into a tithi or European date. (Art. 134 or 149.)

133. For an explanation of the method of calculating tithis and half-tithis (karanas) see Art. 107 above. Our method of calculation for nakshatras and yogas requires a little