Surya Siddhanta
एष्यो हीने गृहे योगो ध्रुवकाद् अधिके ततः। विपर्ययाद् वक्रगते ग्रहे ज्ञेयः समागमः॥
When the longitude of the planet is less than its polar longitude of the constellation the conjunction is to come, when it is greater, the conjunction is past. For planets having retrograde motion, take the contrary as the conjunction.
english translation
eSyo hIne gRhe yogo dhruvakAd adhike tataH। viparyayAd vakragate grahe jJeyaH samAgamaH॥
hk transliteration by Sanscript