Specimen Days is a 2005 novel by American writer Michael Cunningham. It contains three stories: one that takes place in the past, one in the present, and one in the future. Each of the three stories depicts three central, semi-consistent character-types: a young boy, a man, and a woman. Walt Whitman's poetry is also a common thread in each of the three stories, and the title is from Whitman's own prose works.