At noon on Jan. 20, in the shadow of the Capitol, George W. Bush will raise his right hand, place the other on the Bible and swear to faithfully execute the office of president and preserve, protect and defend the Constitution.

It will be the 55th quadrennial presidential inauguration, an event steeped in history and marked by all the pomp and pageantry with which Americans have come to associate the oath-taking ceremony. Heightened security, a constant in this age of terrorism, also will be part of the first inaugural since the attacks of Sept. 11, 2001.

Here, in question and answer form, is a look at the inauguration:

Q: Why is the inauguration on Jan. 20 at noon?

A: The Constitution's 20th Amendment, passed by Congress March 2, 1932, and ratified by the necessary states on Jan. 23, 1933, set the date and time.

The president had been sworn in on March 4, typically the final day of the congressional session. For practical reasons, the nation's forefathers had chosen that date because it took weeks to collect and count the votes, and then weeks by coach or horse for the president-elect to get to the capital.

The change also reflected the desire to limit the lame-duck congressional session, which the outgoing president and members of Congress found to be an "unproductive period of time," according to Betty Koed, the assistant U.S. Senate historian.

In the 1930s, Sen. George Norris, R-Neb., suggested the 20th Amendment, and lawmakers agreed. Koed said there were several reasons for the date. It was about two weeks after Congress counted the electoral votes. Also, calendars indicated that at least for the next few years, the inauguration would not fall on a Sunday -- a day of religious services for many -- and weather patterns showed favorable conditions.

High noon seemed appropriate for a change in command.

Q: Does the chief justice of the United States always administer the oath of office?

A: Traditionally, at the official Washington ceremony, the chief justice administers the oath. Chief Justice William H. Rehnquist has accepted Bush's invitation to administer the oath despite begin treated for thyroid cancer.

In special circumstances, others have sworn in a president. On Nov. 22, 1963, after President Kennedy was assassinated, U.S. District Judge Sarah T. Hughes administered the oath to Lyndon B. Johnson aboard Air Force One at Love Field in Dallas. Hughes was the first woman to administer the oath.

On April 30, 1789, when George Washington was sworn in on the balcony at Federal Hall in New York City, not a single justice had been appointed to the Supreme Court. Robert R. Livingston, chancellor of New York state, administered the oath. ...