Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 9 · Vastu, Griha Pravesha
वास्तु गृहप्रवेशश्च
श्रीप्रदं सर्वगीर्वाणस्थापनं चोत्तरायणे ।गीर्वाणपूर्वगीर्वाणमत्रिणोर्दृश्यमानयोः ॥ ५२४ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 524.
Setting up all the gods brings wealth. Do it in the uttarayana (the Sun's northward course). Jupiter and Venus should both be visible.
Simple meaning: Install gods while the Sun moves north and Jupiter and Venus are both visible.
विचैत्रेष्वेव मासेषु माघादिषु च पंचसु ।
Install gods in Magha, Phalguna, Vaishakha or Jyeshtha. In the dark half, only the first eight days are good.
दिनेषु यस्य देवस्य या तिथिस्तत्र तस्य च ।
Use each god's own moon day. The 2nd, 3rd and 5th to 7th days are good.
दशम्यादेश्चतसृषु पौर्णमास्यां विशेषतः ।
Days 10 to 13 and the full moon are good. So are certain stars like Hasta and Pushya.