Hi everyone,

I'm somewhat annoyed by some of the sentences in my book:
Дело в том, что ____________ ("on") 3 дня, _____________ (29.08.), прилетаю в Москву.

Some steps first (without the exact date)
Дело в том, что через три дня я прилетаю в Москву. - Well, the thing is, I'm gonna be in Moscow (arriving by plane) in three days. (sry, ENG is not my native lang.)
Дело в том, что на три дня прилетаю в Москву. - Well, the thing is, I'm gonna be in Moscow (arriving by plane) for three days.

Right, in this case, we got the additional information on when exactly this will happen (29.08 ).
The book solution is "Дело в том, что на три дня, ..."
Right, makes sense since they say "on" which in fact implies "for".

Couldn't I (also) say "Дело в том, что через три дня, 29.08, прилетаю ..."?
I know the prepositions in question, but somehow have my doubts because of an additional detail that's separated by a comma (a topic that I try to handle with respect in Russian - what works in ENG or something else doesn't necessarily work in RU)

In other words, does через sound weird?
Without the additional information, 29.08., it wouldn't be. It would just mean something else, i.e. "in three days".