Vyasasmriti 1.17

1.17

sīmantaścāṣṭame māsi jāte jātakriyā bhavet
ekādaśe'hni nāmārkasyekṣā māsi caturthake

the parting of the hair in the eighth month; when [the child] is born, the birth rite takes place;
on the eleventh day, the naming; looking at the sun in the fourth month;