The Age of Miracles by Karen Thompson (Paperback)

it's not just her own world that has turned on its head. Julia and her parents wake one ordinary Saturday to discover that the rotation of the earth has suddenly begun to slow. No one knows why, no one knows how to deal with it. Their 24-hour day grows longer, first in minutes, then in hours, until day becomes night and night becomes day. As Julia's family, then her community, fragments, she must navigate both the normal disasters of everyday life, and an ever-terrifying new world.