Learn English – Use of “theirs” in a sentence

Your intuitions are correct that only the temporal measures can be possessive without "worth". CGEL p. 470 calls these measure genitives:

[46] [an hour's delay], [one week's holiday], this [hour's delay], a second [one hour's delay], the [one dollar's worth of chocolates] he bought

Genitives of this kind measure just temporal length or value: we do not have, for example, *They had [a mile's walk] (spatial distance) or *We bought [a pound's carrots] (weight). Value measures take the noun worth as head, while the temporal ones allow any semantically appropriate noun as head. An alternative means of expressing measure is to use a compound adjective, as in a [two-hour delay], a [five-mile walk], an [eight-pound baby], etc.; this is less restricted than the genitive, though it is not admissible with worth.