16. TROPICAL INITIAL POINT
OF THE TIME CYCLES
From the beginning of the kalpa up to the present kaliyuga epoch there
are 4567 intervals of a kaliyuga calculated as follows:3
A week of seven precessional years is 180000 sidereal years (see Chapter 13). From the beginning of the kalpa up to the present kaliyuga there are1 introductory dawn = 4 kaliyugas 6 manus × 714 = 4284 " 27 caturyugas × 10 = 270 " 1 krtayuga = 4 " 1 tretayuga = 3 " 1 dvaparayuga = 2 " -------------- 4567 kaliyugas of 432,000 sidereal years
From the beginning of the present week of precessional years to 1 January 2000 mean Greenwich noon, Julian date 2451545.0, there are4567(432000) ------------ = 10960.8 weeks of precessional years. 180000
tropical years. Taking the fraction of a tropical year and counting backward 0.5291 tropical years from 1 January brings the calendar date to 21 June, the day of the summer solstice.0.8(180000)(365.2563795) + (2451545.0 - 588470.5662) ---------------------------------------------------- = 149106.5291 365.2421756
If we call the tropical year initial point of Hindu cosmological time cycles from the beginning of the kalpa a mean summer solstice, the derived fixed initial point of the sidereal sphere used in the construction of Hindu cosmological time cycles, which is then conjunct to it, is very close to the full Moon point of the fixed initial point given in the SuryaSiddhanta commentary. Henceforth, therefore, we shall consider the initial point of the sidereal sphere for Hindu cosmological time cycles to be the sidereal position of the mean Sun at the mean summer solstice of the year
before the kaliyuga epoch. In a fictitious true tropical calendar the date of this event would have been 21 June 147108 B.C.0.8(180000) = 144000 sidereal years or 365.2563795 144000 · ----------- = 144005.6 tropical years 365.2421756