Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 7 · Samskara Muhurtas
संस्कारमुहूर्ताः
तस्मिञ्जन्ममुहूर्तेऽपि सूतकांतेपि वा शिशोः ।जातकर्म प्रकर्तव्यं पितृपूजनपूर्वकम् ॥ ३२६ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 326.
Do jatakarma (birth rite) for the child at that very moment of birth. Or do it when the birth impurity ends. Begin with worship of the ancestors.
Simple meaning: The birth rite is done at the birth hour or when the birth impurity ends, after honouring the ancestors.
सूतकांते नामकर्म विधेयं तत्कुलोचितम् ।
Name the child when the impurity ends, in the way the family follows.
देशकालोपघाताद्यैः कालातिक्रमणं यदा ।
If the time is missed, do the rite when Venus and Jupiter are visible and the Sun moves north.
चरस्थिरमृदुक्षिप्रनक्षत्रे शुभवासरे ।
Choose a moving, fixed, soft or quick star on a good weekday, when the child and father have Moon and star strength.