Longines Chronoscope, also titled Chronoscope, is an American TV series, sponsored by Longines watches, that ran on CBS Television from 1951–1955. The series aired Monday nights at 11 p.m. ET to 11:15 p.m., and expanded to Mondays, Wednesdays, and Fridays at 11 p.m. ET after the first season. More than 600 episodes were aired, but only 482 survive, and these surviving kinescopes were donated by Longines to the National Archives.