@fantazo Totally forgot about that one. Yeah, that is nice for language learners, it’s always so hard to keep track of the huge number of overlapping metaphorical meanings of different prepositions, where prepositions used in each situation are very case-by-case.

I find it interesting in this post they seem to claim that the use of “en” for “in a given time period” has a clear meaning, but “je” is used for “at a specific time”. I kinda feel like you either say that a specific spatial metaphors make sense about each phrase, or you should use “je” for both, since the preposition doesn’t provide additional information.

For a specific day, you have “before”, “after” and “around” where the meanings would be clear and would be made ambiguous if you swapped them around, but if you swapped out “at” or “in” for “on” with “this day”, it would sound wrong, but the metaphor would be roughly the same.