The 20th Amendment is an amendment to the US Constitution, the primary governing document of the US, and it was ratified on 23 January 1933. It applies specifically to federal officials and sets forth the beginnings and ends of their terms. It further makes provisions for circumstances in which no president-elect is present.
The purpose of this amendment is primarily to specify the exact time of transition from one body of elected officials to the next. Specifically, the terms for the incumbent president of the United States and for the incumbent vice president end at precisely noon on 20 January every four years. The term of the president-elect and the term of the vice president-elect begin at that same time.
The terms of incumbent members of the US House of Representatives and the terms of incumbent US Senators end on 3 January of the year in which the term is intended to end. Incoming officials take office at that same time. Members of the US House of Representatives serve two-year terms, and US Senators serve six-year terms. Both are elected on rotating schedules.
These dates significantly shortened the time between the election of a new president and the time at which he or she takes office. Prior to the ratification of the 20th Amendment, the president and vice president did not take office until 4 March. The primary purpose of shortening the time frame was to ensure that the business of government was not impeded by a delay in office-taking. Additional sections of the amendment provide that Congress must convene at least once each year, and that the session begins on 3 January.
One provision of the amendment stated that it could not be considered law unless ratified within seven years of its proposal. The amendment was proposed on 2 March 1932, and was ratified by the first state, Virginia, on 4 March of the same year. Utah ratified it on 23 January 1933, providing enough states to formally amend the US Constitution. By 26 April 1933, all 48 states then in existence had ratified the amendment.
Another important provision of the amendment involves the president-elect. It states that if the president-elect dies before taking office, the vice president-elect shall take office in his place. If a new president has not been chosen or if the president-elect fails to qualify before taking office, the vice president-elect will become the president pro tem until a new president is elected.