I think I am exactly the wrong audience for this book. I read a lot of science fiction, see, and this book is very much trying to do science fiction without the science fiction. And so my inclination is to want the book to explore at least some of the science behind what's going on, and the steadfast half-refusal to do so is irritating.
I'm fine with eventually scientists saying "we don't know why this is happening," but come on, they don't even have any hypotheses? None? Zero? Really? I call bullshit.
There are also lots of notes saying that "later we would understand that X-Y-Z" about the effects of the phenomenon in the book, but they're never gotten into, never explored, their repercussions just left to float off into the ether. And in at least one case, one seems to be directly contradicted by what goes on in the story - there's a mention that the circadian rhythm is more malleable than we had thought, and that time would bear out the real-timers as the healthier choice. But that isn't remotely what happens.
So, anyway, the earth's rotation is slowing and no one knows why. (Again, I'm fine with it being a mystery, but I do not believe for a second that scientists would simply throw their hands up in the air and say "I guess it's a mystery!") Days grow longer, by ragged chunks. Some days grow longer by hours, others by minutes. But it happens.
(Side note: I also didn't get why there would be such massive tides, since she never went into how this slowing of the rotation affected the moon. Why would the moon's passage over the skies change too? If you want to have that Be A Thing, you have to tell me that and a little bit of why. If not, you make my inner nerd cranky.)
Julia is an early teen, and caught in the middle of a world that is dying with a whimper, not a bang. Her family tries to hold it together, her mother by worrying, her father pretending that everything will be fine. Her Mormon best friend moves away from California to Utah to await the end. The government eventually decrees that everyone needs to move back to "clock-time," detaching experience from the rising and setting of the sun. "Real-timers" refuse.
There are lots of good ideas here that I wished were explored more. Instead, they're sort of shoved aside for the atmospheric gloom of a world on the edge. But that atmospheric gloom is fairly well done, although there was at least one narrative tic that drove me crazy. At least twice, the young narrator says something like "if I'd known how long it would be until I saw her again, I would have done things differently," and both times, "how long" turns out to be about two weeks. Really? If you'd only know it would be two whole weeks until you saw her again, you'd have done what differently? Have you never gone on a summer vacation before? Two weeks ain't that long.
In that way, the narrator, writing from the future back about her younger days, speaks weirdly about things in ways that aren't borne out by the actual occurrences in the book.
I'm absolutely the wrong audience for this book. But the lack of exploration of what was going on in favour of how it slowly affected a family, well, I'd like to think I could enjoy this, but enough was left unexamined in this book that it nagged at me instead. Perhaps if you aren't a science fiction fan, you might enjoy this more.
Crossposted to Smorgasbook