Skandapurana 5.76.72

5.76.72

trayāṇāmapi teṣāṃ tu sādhvarcāḥ śāstrasūcitāḥ..
sthāpayāmāsa sūryāṇāṃ hastārke sūryavāsare ... 72 ..

And in them he installed proper images of those three suns, / as prescribed by the scriptures, on a Sunday when the sun was in Hasta. 72