After the ritu becomes known, take the first part of the Drekkana as its first month and latter part as the next month of the ritu. Then from the expired amsas of the Drekkana, determine proportionately the tithi or the amsas of the Sun. The Istakala indicated by the amsas (degrees) of the Sun, will be the time of the birth of the querist. From the Istakala so calculated have to be worked out the longitudes of the planets and houses (Graha spast and Bhava spast). Predictions should then be made in accordance with the dispositions of the houses and planets.

मासो दृकाणपूर्वार्धेर्पूर्वोऽन्यस्तु परार्धके । अनुपातात्‌ तिथिर्ज्ञेया भास्करांशसमा द्विज । ।8।। यदि द्रेष्काण का पूर्वार्ध हो तो ऋतु का पहला मास तथा उत्तरार्ध हो तो दूसरा मास समझें । प्रश्न समय में सूर्य के गतांशों से अनुपात द्वारा द्रेष्काण के पूर्वापरार्ध से जन्मतिथि का निर्णय करें ।