past perfect - "He had had his nap" or "he had his nap"?

I am reading Jonathan Franzen's The Corrections, and I came across this sentence:

He'd had his nap and there would be no local news until five o'clock.

Why did Franzen choose to write the sentence using the past perfect instead of the simple past? My understanding of past perfect is that it is only used to denote an event in the past that occurred before another event. Should I consider the "local news until five o'clock" as that latter event?

I know that the past perfect subjunctive of "have" is "had had," but I do not believe that he is conveying that mood.

Answer

You need the larger context:

Three in the afternoon was a time of danger in these gerontocratic suburbs of St. Jude. Alfred had awakened in the great blue chair in which he'd been sleeping since lunch. He'd had his nap and there would be no local news until five o'clock. Two empty hours were a sinus in which infections bred.

Reference Time for this past perfect is introduced at the beginning of the paragraph: three in the afternoon. At some time before that Alfred had awakened; he had had his nap, so now he had no mindless activity left to occupy the two empty hours between Reference Time, three o'clock, and the next mindless activity, the local news, at five o'clock.