Khandakhadyaka: An Astronomical Treatise

Just as a sweet preparation called khandakhadyaka a specific food item gives pleasure to one who consumes it, so too does this manual give pleasure to the calculator who achieves the [calculation of] planetary motion through very little computation. "I shall explain"—what kind of manual? "Yielding results equivalent to those of the teacher Āryabhaṭa." The treatise composed by the teacher named Āryabhaṭa is the Āryabhaṭa-tantra the treatise of Aryabhata; this manual yields results similar to that. Now, if someone asks, "If this manual yields results equal to Āryabhaṭa's, then what is the purpose of this one?", he replies:

Because the Āryabhaṭa-tantra is expansive, it is not possible to perform daily practice regarding lunar days, asterisms, and the like. Therefore, I have understood the results through brief formulas and calculations. [This is the] Khandakhadyaka. For what occasions is practice not possible? He says, "for marriages, nativities, and the like." By the word "and the like" [it includes] marriages, horoscopes, journeys, lunar days, asterisms, karaṇas half-lunar days, solar ingresses, vyatīpāta a specific astronomical conjunction, eclipses, rising, setting, and conjunctions. Because the work of Āryabhaṭa is too extensive, it is not possible to perform the work. I have understood it through a brief exposition. Now, the teacher explains the determination of the ahargana the count of days:

Here a considerable part of the commentary has been left out in the manuscripts.