Brihat Jataka
दिवारात्रिप्रसूतिं च नक्षत्रानयनं तथा ॥ सप्तकेष्वपि वर्गेषु नित्यमेवोपलक्षयेत् ॥ २६-१३ ॥
Always indeed thus one should consider the day or night birth and calculating the nakshatra in the group of seven.
english translation
divArAtriprasUtiM ca nakSatrAnayanaM tathA ॥ saptakeSvapi vargeSu nityamevopalakSayet ॥ 26-13 ॥
hk transliteration by Sanscript