Our only direct reference to Henderch's dates is to the voyage of the vessel Hirilondë, the ship on which he served as a mariner under the Great Captain Aldarion. He sailed from Númenor on that ship in II 877, and returned five years later in II 882. To serve as a sailor, Henderch must have been born some decades before II 877, and there is no reason to imagine that he did not live long after the ship's return, but we have no specific evidence for him outside this brief range of dates in the ninth century of the Second Age.

The meaning of Henderch's name is not explained, nor is its derivation by any means obvious, though it seems to contain hen(d), meaning 'eye' (as, for example, in Amon Hen, the 'Hill of the Eye'). The ending -erch would normally mean 'spine' or 'thorn', but this does not seem to be particularly meaningful as part of a personal name. Conceivably the name was intended metaphorically as meaning something like 'sharp-eyed', though this is necessarily rather speculative.