O Nārada, listen with attention as the ancient sages speak of the subtle art of determining the span of life through the movements of the heavens. The reckoning begins by considering the nakshatras, the Moon, the two lunar halves, and even the subtle measures perceived by the senses and the crown of the head. When the celestial circle is pure and unblemished, the portions to be taken are those that have been agreed upon by tradition for the calculation of longevity. If a planet is found in the regions of Manda or Shukra, or if it has set, then only half its portion is considered, not the full measure. Further, one must set aside the portions belonging to enemy planets, taking only the remainder for the calculation of life. The shares attributed to malefic planets are never taken in full, while those of benefic planets are taken whole, without halving. As the years are counted, the remaining years—after subtracting from the solar years—are to be considered as months, and so on. When this remainder is divided by sixty, the quotient gives the number of months, while the leftover reveals the days, hours, and even finer divisions. Alternatively, the remaining years may be multiplied by twelve and so forth, to yield the corresponding months and other measures. If a planet lacking longevity is joined to the ascendant, its portion of life is to be subtracted. When a planet is situated in the ascendant or the sixth house, the calculation must be adjusted accordingly, not following the previous method. If there is equality among the planets, their shares remain; otherwise, the share of that planet is not granted. The portions of life are determined by multiplying the relevant factors, and this process is known as the calculation. When the remainder is divided by two hundred, the quotient gives the months, and the leftover is apportioned into days and so forth. If the remainder is divided by the product of the Sun and other planets, the outcome is the months, days, and so on, each according to its direction. To refine the result, the portion is divided by the number of degrees, and this figure is multiplied by the months and by the product of the signs from the ascendant, yielding the final result. Among the ascendant, Sun, and Moon, whichever is strongest, its period comes first. The one with the greatest longevity, or with equal strength among the Sun and others, receives the first period. Attention must also be paid to the seventh and fourth houses, and to those planets situated in the quadrants. The fruits of the seventh and fourth, and of those in the oceanic signs or the same group, are to be considered. For the fourth and eighth, the multipliers are established as those of heaven. When the remainder is divided by the product of the Sun and others, the months and so on are obtained in unity, O Nārada. The period increases by the number of years, months, and so forth, according to the lordship, friendship, exaltation, own sign, Moon, year, and mountain. Should a planet be situated elsewhere as described, it causes the destruction of the corresponding result. All results related to livelihood and other matters should be considered during its period. If a planet is aspected by benefics, is mobile, and found in a favorable group, the outcome is auspicious and complete, especially if arising from the eighth group. If, however, a planet is in its own trine or with a friend, the result is moderate, not excellent. Should it be in an unfavorable or harsh location, or in a desirable place but weak, then the result must be declared as slight. In a fixed sign, the result is unfavorable in the eighth and middle places; the outcome for the hour is threefold according to the divisions. If a planet is joined with destructive aspects or found among malefics, the result is otherwise—often inauspicious. When Venus and others are retrograde, in their own, exalted, or solar positions, the result is sixfold. Those situated at the end, who are learned or wise, from there increase or become connected with relatives. From their own, exalted, or similar positions, if joined with the eighth or fifth, the result is as described. From the center, eighth, or end, or from the worshipped, the result follows the planet’s own measure. One who is in the center, eighth, or apart from these, in their own sign, or with Saturn, or in the center with a group, is to be considered accordingly. If situated in karma, ayana, or the sixth, then Mars with Jupiter is considered auspicious. Directly, those who are from Mars, Jupiter, or in the twelfth, sixth, or eighth from the ascendant, as well as those in the sixth, eighth, or twelfth, yield results as per their conjunctions from the ascendant. In the third division, with the Sun, or from Venus, if in the twelfth, the result is as per the direction, enemy, or birth. Those who are with the Moon, Jupiter, or in the sixth or twelfth, are to be regarded as immediately weak from the ascendant. Thus, O wise one, is the intricate tapestry of longevity and results woven from the positions and strengths of the heavenly bodies, each revealing its own portion of fate according to the eternal science.