What is the meaning of this ということだ


For full context:

[![enter image description
here](https://i.stack.imgur.com/9WIWd.png)](https://i.stack.imgur.com/9WIWd.png)

> 僕たちは一つだけ決めていることがある。 それはよる10時を過ぎたら、自分の部屋で過ごすということだ.

I think this ということだ expresses "means". "Concerning this...it means (that)".
I'm asking for confirmation because my textbook also teaches ということだ as a means
to express hearsay or to summarize what the partner in dialogue just said.

My attempt at translation: "Concerning this, it means that when it is past 10
o'clock in the evening, I/we (?) pass time in my/our own room(s)."




The phrase ということだ does have several idiomatic uses, like indicating hearsay
and paraphrasing, but it is not the case with this particular ということだ. Overall
meaning of the sentence will be clear by just adding up those of its component
words (if we treat ということ as one word having the function of nominalization,
that is). The basic structure of the sentence is almost as simple as that of
「私は学生だ。」("I am a student."):

それ(Topic Noun) + は(Topic Marker) + よる...ということ(Predicate Noun) + だ(Copula)

Translation:

> There is just one rule we agree upon. **It is that we spend time in our own
> respective rooms after 10 p.m.**

It's just that your sentence has a predicate noun with ということ, followed by だ,
and ということだ can have different interpretations in different cases, unlike 学生だ,
which always means _be a student_.




The phrase ということだ does have several idiomatic uses, like indicating hearsay
and paraphrasing, but it is not the case with this particular ということだ. Overall
meaning of the sentence will be clear by just adding up those of its component
words (if we treat ということ as one word having the function of nominalization,
that is). The basic structure of the sentence is almost as simple as that of
「私は学生だ。」("I am a student."):

それ(Topic Noun) + は(Topic Marker) + よる...ということ(Predicate Noun) + だ(Copula)

Translation:

> There is just one rule we agree upon. **It is that we spend time in our own
> respective rooms after 10 p.m.**

It's just that your sentence has a predicate noun with ということ, followed by だ,
and ということだ can have different interpretations in different cases, unlike 学生だ,
which always means _be a student_.

