An American author, he is best known for his autobiographical trilogy of God and My Father (1932), Life With Father (1935), and Life with Mother (1937). His other works include The Crow's Nest (1921) and Thoughts Without Words (1928).
He attended Yale University and published his first book, The Story of the Yale University Press, in 1920.
He was a regular contributor to The New Yorker.
He had a daughter, Wendy, with his wife, Katherine Briggs Dodge. He was born in New York City to Clarence Day and Lavinia Stockwell.
His novel, Life with Father, was adapted into both a film starring Elizabeth Taylor and a Broadway play.