The Time Keepers by Alyson Richman

 This lovely book alternates between the stories of Ahn and Bao, refugees from Vietnam, Grace and Tom, who live in a small town on Long Island, and Jack, a Vietnam vet who was badly injured during the war.

Their paths cross when Grace finds young Bao lost and alone. She finds out he is living at a Catholic convent with other refugees and his aunt Ahn. Grace returns the boy and decides to volunteer with the refugees, forming a fast friendship with Ahn. Tom owns a watch repair shop that has become a refuge for Veitnam vet Jack, who helps with the repairs. Eventually all of their lives are intertwined and they all help each other get past their ghosts and move forward.