January 23, 1933
Amendment 20 ratified
Amendment 20 was passed by Congress on March 2, 1932, and ratified by the states on January 23, 1933. The most notable part of the amendment was Section 1 where the Presidential and Vice Presidential terms of office changed from March 4 to January 20.
Section 1: "The terms of the President and Vice President shall end at noon on the 20th day of January; and the terms of Senators and Representatives at noon on the 3rd day of January, of the years in which such terms would have ended if this article had not been ratified; and the terms of their successors shall then begin."
Constitution of the United States, Amendment 20, Section 1