Chudakarana's procedure and timing are set out in the same Grihya Sutra literature that codifies the wider set of samskaras, and the underlying rationale generally given for removing a child's birth hair connects it to ideas about impurity or residue carried over from a prior existence, so that the ritual shaving is understood to mark a genuine fresh start rather than simply being a practical grooming milestone.
In its older, fuller form the rite left behind not just a shaved head but a retained tuft, the shikha, at the crown, a lifelong marker of ritual status that observant Brahmin men in particular were expected to maintain, uncut, for the rest of their lives as a visible and permanent sign of their sacramental identity rather than something confined to childhood. That lifelong dimension of the custom has receded sharply across most of modern Hindu society, as Western style haircuts and dress became common even among otherwise observant families over the nineteenth and twentieth centuries, so that the childhood ceremony itself, the first shaving performed in the first or third year, continues to be widely observed in something close to its old form, while the shikha it once left behind as a permanent adult marker is retained afterward by only a comparatively small number of priests, ascetics, and traditionalist households rather than by Hindu men generally.