I'm not sure, but this sounds like an example of Begging the Question. I'm probably forgetting how this thread is progressing. When a days or even years are mentioned, they can be figuratively referring to less than complete days or nights, but when nights are mentioned in addition to days, those nights are included. In other words, we're not dealing with figurative speech when nights and days are mentioned.
On the other hand, to say "three days" or "three years" doesn't necessarily mean we are figuratively speaking about less than three whole days or years. When the literal days and nights are mentioned we know that the other accounts are not figurative.