Indian Chronology (Solar, Lunar and Planetary): A Practical Guide to the Interpretation and Verification of Tithis, Nakshatras, Horoscopes and other Indian Time-records, B.C. 1 to A.D. 2000 c14.7

c14.7

(1) CORRECTION FOR TERRESTRIAL LONGITUDE.—If the sun moved uniformly along the celestial equator, all places on earth would have sunrise at exactly 6 a.m., local time. On this supposition local time for any moment of the day could be deduced from Laṅkā time by adding or subtracting four times as many minutes of time as there are degrees of longitude between Laṅkā (or Ujjain) and the given place. The longitude of Ujjain being 76° East of Greenwich, any place whose longitude is more than 76° from Greenwich has a positive correction, and any place whose longitude is less than 76° has a negative correction for terrestrial longitude. For example: the longitude of Madras being 80¼° East of Greenwich, *i.e.*, 4¼° more than Ujjain, local time at Madras is obtained from Laṅkā time by adding 4¼° × 4' = 18 minutes of time.