A perfect day / by Richard Paul Evans.

Enhanced descriptions from Syndetics:

One of the world's most beloved authors returns with the story of a man who found everything he thought he was missing in the family he already had. Robert Harlan has three loves in his life: his wife, Allyson, his daughter, Carson, and his writing. As a sales rep for a small radio station, he has hopes of one day leaving it all behind for a successful writing career. When he is unexpectedly laid off from his job, Allyson encourages him to pursue his dream of writing. He writes a novel entitled A Perfect Day, based on the last few months Allyson and her father spent together as he died of cancer. The story becomes a huge success and Robert finds himself swept into a new world far from his wife and home. In time Robert loses track of the things he loves most...until he meets a stranger who begins telling him intimate details about his past, his present and, most important, the brevity of his future. Thinking that he has just months to live, Robert begins to discover the truth about himself; who he has become, what he has lost and what it will take to find love again. A Perfect Dayis a novel of love and awakening from one of the world's most beloved storytellers.