This is the debut novel of Karen Thompson Walker. It is a coming -of-age tale of Julia, a California tween who suddenly finds herself in uncertain times. The Earth's rotation is slowing, which affects the gravitational field, the magnetic field, the tides, the weather, people's health.... At first, though, all it seems to affect is length of days and nights.
I found this novel incredibly disheartening. It seems to end abruptly; one moment Julia is 12, the next 23. And in spite of the title, there are no miracles here. Unless it's the one where people just keep putting one foot in front of the other despite the circumstances. Maybe a miracle after all.