133 menon is called (Tata) vyatipāta; when that (sum) amounts to a circle (i.e., 360°), the phenomenon in called vaidhṛta (vyatipata); and when that (sum) extends to the end of the naksatra Anuradha (i.e., when that sum amounts to 7 signs, 16 degrees, and 40 minutes), the phenomenon is called sārpamastaka (vyatipāta). VYATIPATA The (Tata) vyatipata occurs when the Sun and Moon are in different courses of motion (ayana)¹ and their (true) declina- tions are equal. Its region is half a circle, but due to the Moon's latitude it may be more or less.² The sarpamastaka vyatipăta corresponds to the yoga known by the name vyatipāta. That the region of the (lata) vyatipāta is half a circle means that the (lāṭa) vyatipāta takes place when the Sun and Moon are within half a circle measured from the first point of nakṣatra Asvini. The phenomena of vyatipāta (usually called pata or mahāpāta) are treated in detail in later works. In the Surya-siddhānta, Brāhma-sphuta- siddhānta, Siddhānta-šekhara, and Siddhānta-śiromaņi, etc., a whole chapter is devoted to that subject. In modern Hindu Calendars (called Pancanga) are given the tithi, karana, Moon's nakṣatra, and yoga current at sunrise for every day of the year and also the times when they end and the next ones begin. The yoga has not been treated by Bhaskara I, but it forms one of the five important elements of the Hindu Calendar. Like the nakṣatras, the number of these yogas is also twenty-seven. The method of finding the yoga passed over and the time elapsed at sunrise since the commencement of the current yoga is similar to that prescribed for the naksatra. The difference is that in the case of the yoga calculation is made with the sum of the longitudes of the Sun and the Moon, whereas in the case of the naksatra calculation is made with the help of the longitude of the Moon only. The first yoga (called Viskambha) begins when the sum of the longitudes of the Sun and moon is zero, the second yoga (called Priti) begins when ¹ That is to say, when one has northward motion and the other has southward motion. ² For details, see Sisi, I, xii.
