Timbers was nominated by President Richard Nixon on May 13, 1971, to a seat on the United States Court of Appeals for the Second Circuit vacated by Judge Robert P. Anderson. He was confirmed by the Senate on July 29, 1971, and received his commission on July 29, 1971. He assumed senior status on July 10, 1981. He took inactive senior status in the summer of 1993. His service terminated on November 26, 1994, due to his death.Arnold H. Lubasch, Judge Timbers Leaving U.S. Appeals Court Post, New York Times (July 17, 1981).
