Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 7 · Samskara Muhurtas
संस्कारमुहूर्ताः
चतुर्थे मासि षष्ठे वाप्यष्टमे वा तदीश्वरे ।बलोपपन्ने दंपत्योश्चंद्रताराबलान्विते ॥ ३२१ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 321.
Do the hair-parting rite in the 4th, 6th or 8th month, when that month's lord is strong. The couple should have Moon strength and tara (star count from the birth nakshatra) strength.
Simple meaning: Choose the 4th, 6th or 8th month, when the Moon and the stars suit both parents.
अरिक्तापर्वदिवसे कुजजीवार्कवासरे ।
Pick a day with no empty or junction tithi, on Tuesday, Thursday or Sunday, with the Moon in a male navamsha.
शुद्धेऽष्टमे जन्मलग्नात्तयोर्लग्ने न नैधने ।
Keep the 8th house clean, avoid the 8th from either parent's birth lagna, and let good planets support the rising sign.
शुभग्रहेषु धीधर्मकेंद्रेष्वरिभवे त्रिषु ।
Good planets in the 5th, 9th and corners, bad ones in the 3rd, 6th, 11th, and the Moon in a good house.