Kore wa nan desu ka?
I was loooking for a long post as such.
I see...naturally, as I expected in the beginning, the initial ambiguity was eventually solved with prepositions.To learners of the language, it seems natural that no native speaker would misinterpret diebus as 'by means of days', and yet we see in diebus or per dies or what have you, so that this misinterpretation is made impossible.