Day of Anger (Italian: I giorni dell'ira), also known by its UK video title Gunlaw, is a 1967 spaghetti western film directed by Tonino Valerii. The film stars Lee Van Cleef and Giuliano Gemma, and features a musical score by Riz Ortolani. The film is based on the novel Der Tod Ritt Dienstags by Ron Barker. Day of Anger was Valerii's second film, as well as his second spaghetti western, following Per il gusto di uccidere (Taste for Killing, 1966). Valerii went on to film his third spaghetti western,Il prezzo del potere (The Price of Power), also featuring Gemma, in 1969.