Overdue by Stephanie Perkins

Ingrid Dahl is a bubbly 29-year-old library staffer at the North Ridgetop Branch Library who for four years has shared the Circulation Desk with Macon Nowakowski, known for being somewhat grumpy to patrons, although not to Ingrid. When Ingrid’s younger sister gets engaged, she and her long-time boyfriend Cory start talking about marriage themselves and realize they aren’t ready. Because they’ve been together since they were 18, they decide to take a break for a month and date other people, then decide if they want to get married.