United States presidential inauguration

The inauguration of the President of the United States is a ceremony to mark the commencement of a new four-year term of a president of the United States. This ceremony takes place for each new presidential term, even if the president is continuing in office for a second term. Since 1937, it has taken place on January 20, which is 72 to 78 days after the November presidential election (on the first Tuesday after November 1). The term of a president commences at noon (ET) on that day, when the Chief Justice administers the oath to the president. However, when January 20 falls on a Sunday, the Chief Justice administers the oath to the president on that day privately and then again in a public ceremony the next day, on Monday, January 21. The most recent presidential inauguration ceremony was the swearing in of Donald Trump to a four-year term of office on Friday, January 20, 2017.

The only inauguration element mandated by the United States Constitution is that the president make an oath or affirmation before that person can "enter on the Execution" of the office of the presidency. However, over the years, various traditions have arisen that have expanded the inauguration from a simple oath-taking ceremony to a day-long event, including parades, speeches, and balls.

Since the 1981 inauguration of Ronald Reagan, the ceremony has been held at the west front of the United States Capitol. Other swearing-in ceremonies have taken place at the Capitol's east portico, inside the Old Senate Chamber, the House chamber, and the Rotunda. Additionally, on two occasions—in 1817 and 1945—they were held at other locations in Washington, D.C..

Although the Constitution does not mandate that anyone in particular should administer the presidential oath of office, it is typically administered by the chief justice. Since 1789, the oath has been administered at 58 scheduled public inaugurations, by 15 chief justices, one associate justice, and one New York state judge. Others, in addition to the chief justice, have administered the oath of office to several of the nine vice presidents who succeeded to the presidency upon their predecessor's death or resignation intra-term. When a new president assumed office under these circumstances the inauguration is kept low key, and conducted without pomp or fanfare.

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