Discernment of the Truth of Astronomical Principles

Calculation of Intercalary Months and the Day-Count

When the accumulated months from the beginning of Chaitraoriginal: caitra; the first month of the Hindu lunar year, usually occurring in March-April are fifteen, they should be used to calculate the Ahargaṇaoriginal: ahargaṇa; the "heap of days," or the total count of days elapsed from a specific cosmic epoch to the desired date. If the weekday does not align with the end of the Great Age, the wise astronomer should add or subtract one day as needed. 15 The clear intercalary months should be known through this method. If the count is obtained differently, the number of Adhimāsasoriginal: adhimāsa; intercalary or "extra" months added to the lunar calendar to keep it synchronized with the solar seasons should be adjusted sequentially by addition or subtraction. 15

The revolutions of the Sun from the beginning of creation and the start of the Kali Ageoriginal: kali; the current cosmic age in Hindu chronology are multiplied by the total number of days and divided by the specific divisors mentioned in the manuals. The result provides the number of revolutions, signs, and degrees. 16 From these, the Mean Sun and other planets are derived. The Mean Sun is traditionally calculated from midnight. These results, including minutes and seconds, are then used to determine the specific positions of the planets. 17

Constants for Planetary Corrections

For the desired calculations, the following numerical values These appear to be astronomical constants or mean longitudes used for specific epoch corrections are established:

These values are applied to one's own calculations after accounting for the solar days, weekdays, and intercalary months. 20 In any desired year, these figures should be multiplied by the specific years being calculated to make them suitable for practical use. The Kuvāsarāḥoriginal: kuvāsara; terrestrial or "earth-days," representing the time for one full rotation of the Earth of the solar year are then calculated using these days and fractions. 21

The Lord of the Year and the Lord of the Day

The "Lord of the Year" is determined based on the elapsed years. The wise state that this is essential for calculating the positions of the Grahagaṇaoriginal: grahagaṇa; the assembly or group of planets. To find the planetary positions, one must first establish the day-count based on these solar years. 22 Because the day-count is the primary factor derived from the solar years, the calculation of the weekday always begins with the "Lord of the Year." 23

The current planetary positions are not based on the time already passed, but rather on the "Lord of the Year" and the remaining time. 24 This solar year cycle is uninterrupted. When the desired time arrives, the astronomer calculates the elapsed time from the rising of the Sun and the "Lord of the Year." 25 Without this determination, there remains a doubt regarding the "Lord of the Year"; therefore, the calculation of the weekday is used to ensure the success of the mathematical operation. 26

Corrections for Sunrise and Visibility

The day-count is first calculated using the Madhyama Sāvanaoriginal: madhyama sāvana; the mean terrestrial day (mean solar day). Then, the results produced from the terrestrial day must be adjusted—either subtracted or added—by the Udyāntaraoriginal: udyāntara; the "equation of time" or the difference between mean and true sunrise correction. 27

When the Sun rises, the specific calculation for the Sun must be known. One must then determine the motion of the Mean Sun and subtract the necessary parts to find the true position. 28 The difference between the two, when multiplied by the planetary velocity and divided by the duration of a day and night, provides the result in minutes and seconds. 29 These are the seven methods of calculation... The text breaks off mid-sentence