Can the past progressive tense ever "overlap" into the present time?


I know that the tense of [Japanese subordinate
clauses](https://japanese.stackexchange.com/questions/25376/how-to-
appropriately-pair-tenses-in-subordinate-and-main-clauses) is always relative
to the time the main clause happens (which is different than in English). But
consider the following:

> 子供が[昼寝]{ひるね}をしていた

Consider now _two_ interpretations of this statement:

  1. **Interpretation (A).**

> [![enter image description
> here](https://i.stack.imgur.com/H2gN4.png)](https://i.stack.imgur.com/H2gN4.png)

  2. **Interpretation (B).**

> [![enter image description
> here](https://i.stack.imgur.com/s9rCq.png)](https://i.stack.imgur.com/s9rCq.png)

Are both (A) and (B) potentially correct interpretations of the sentence? The
reason I ask this is because I'm trying to understand how

> 子供が昼寝をしていた間に、本を読み終えた。
>
> _While_ the kids were taking a nap, I finished reading a book.

can possibly make sense _without_ interpretation (B) being permissible. As I
see it:

  1. **The sentence under interpretation (A).** This doesn't make any sense:

> [![enter image description
> here](https://i.stack.imgur.com/f9Hg6.png)](https://i.stack.imgur.com/f9Hg6.png)
> 2. **The sentence under interpretation (B).** This does seem to make sense:
> [![enter image description
> here](https://i.stack.imgur.com/NjYGS.png)](https://i.stack.imgur.com/NjYGS.png)

So the only way this sentence possibly makes sense is if we force
interpretation (B) on 「子供が昼寝をしていた」, no?

**NOTE:** This sentence is from a tutorial on ~ていた間に from
[IMABI](https://www.imabi.net/whileiaida.htm).




It will depend on context or meaning of the sentence. For your case, yes, (B)
is the only possibility.

Consider

  1. 子供が学校に行っていた間に買い物をすませた。While child is away for the school, I finished shopping.
  2. セールがやっていた間にいろいろ買った. While they have the sale, I bought many things.

For 1, only (B) is possible. Otherwise it does not make sense. For 2, the sale
may or may not have ended. So (A) or (B) is possible.

* * *

FYI using present tense in the subordinate clause (子供が昼寝をしている間に,
子供が学校に行っている間に, セールがやっている間に) does not change the meaning, and is possibly more
natural.




It will depend on context or meaning of the sentence. For your case, yes, (B)
is the only possibility.

Consider

  1. 子供が学校に行っていた間に買い物をすませた。While child is away for the school, I finished shopping.
  2. セールがやっていた間にいろいろ買った. While they have the sale, I bought many things.

For 1, only (B) is possible. Otherwise it does not make sense. For 2, the sale
may or may not have ended. So (A) or (B) is possible.

* * *

FYI using present tense in the subordinate clause (子供が昼寝をしている間に,
子供が学校に行っている間に, セールがやっている間に) does not change the meaning, and is possibly more
natural.

