I vaugely remember Beatrice or someone proclaiming in red or otherwise stating (reliably, not as a trick or anything) that the game takes place during those 2 days in 1986 and ends after the 5th of October. If you're getting this idea from a certian other game, I don't see how it would work anyways since everyone dies...
Also becuase I couldn't put this in the anime discussion threads (only an EP4 spoiler, but has nothing to do with the current discussion)