Surya Siddhanta
इष्टनाडीगुणा भुक्तिः षष्ट्या भक्ता कलादिकम्। गते शोध्यम् युतम् गम्ये कृत्वा तात्कालिको भवेत् ॥
(If you want to know the place of a planet at a given time after or before a given mid-night,) multiply the daily motion of the planet by the given time in Ghaṭikás, divide the product by 60, and add or subtract the quotient, in minutes, to or from the place of the planet found at the given (mid-night,) and you have the place of the planet at the given time after or before the given mid-night. The place of the planet, thus found, is called its Tátkálika or instantaneous place.
english translation
iSTanADIguNA bhuktiH SaSTyA bhaktA kalAdikam। gate zodhyam yutam gamye kRtvA tAtkAliko bhavet ॥
hk transliteration by Sanscript