Question: when did leningrad changed back to st petersburg
Answer: On 1 September 1914 , the name was changed from Saint Petersburg to Petrograd ( Russian : Петрогра́д , IPA : ( pjɪtrɐˈgrat ) ) , on 26 January 1924 to Leningrad ( Russian : Ленингра́д , IPA : ( ljɪnjɪnˈgrat ) ) , and on 7 September 1991 back to Saint Petersburg .