The twilight darkens, the curfew calls, what are they talking about?

I think its referring to a poem called:

the tide rises, the tide falls

I think what they are talking about in this is the darker it gets outside the more dangerous it gets so the kids outside playing should get home by their curfew. Into the safety of their families.

Hope that helped :)

I'm guessing a 'fragment'. read over the sentence and question again before you move on.