Hundreds of thousands of people are expected to stream into Washington on 20 January to watch as President-elect Donald Trump is sworn in as the 45th US president.
All eyes will be on the US Capitol as Trump formally replaces President Barack Obama in the White House.
Here is a guide to the historic transition.
What is a presidential inauguration?
The newly elected US president is sworn into office by the Chief Justice of the United States every four years by noon (17:00 GMT) on 20 January, as prescribed by the US Constitution.
The incoming president was historically inaugurated on 4 March, but the period of delay was shortened when the 20th Amendment was ratified in 1933.
The oath is part of a ceremony marking the peaceful transition of power on the steps in front of the US Capitol.
The ceremony is then followed by a parade down Pennsylvania Avenue and later celebrated through a series of inaugural balls.
19 JANUARY
10:35am (15:35 GMT) A day-long public concert held at the Lincoln Memorial began with performances by the DC Fire Department Emerald Society Pipes and Drums, the Republican Hindu Coalition and high school marching bands
3:30pm (20:30 GMT) Mr Trump and Vice President-elect Mike Pence attended a wreath-laying ceremony at Arlington National Cemetery to honour veterans
4pm (21:00 GMT) Mr Trump delivered remarks during the second half of Lincoln Memorial concert, where country stars Toby Keith and Lee Greenwood performed
20 JANUARY
Trump attends service at St John's Episcopal Church near the White House
Trump and his wife, Melania, have morning coffee with President Obama and First Lady Michelle Obama. The couples will then take a motorcade to the Capitol
9:30am (14:30 GMT) Inauguration ceremony begins with musical performances
11:30am (16:30 GMT) Opening remarks followed by Supreme Court Justice swearing in Mr Pence
11:45am -Noon (16:45 - 17:00 GMT) President Obama's term of office ends at precisely noon. Before then, Trump must recite the oath of office, administered by Chief Justice Roberts. He will then deliver his inaugural address
3pm-5pm (20:00 - 22:00 GMT) Trump and Pence will embark on a 1.5 mile (2.4km) parade down Pennsylvania Avenue, which will probably be lined with supporters and protesters
7pm-11pm (00:00-04:00 GMT) Trump, Pence and their wives will attend three official inaugural balls
21 JANUARY
10am (15:00 GMT) Trump and Pence attend the interfaith National Prayer Service at the Washington National Cathedral
10am (15:00 GMT) The Women's March on Washington begins
Who is going to be there?
President Obama and the first lady will accompany Trump in a motorcade to the US Capitol for the official ceremony, where they will be joined by members of Congress, politicians as well as supporters.
Former President Bill Clinton and Hillary Clinton, who lost to Trump in November's election, are expected to attend.
George W Bush and his wife, Laura, as well as Jimmy Carter have also confirmed they will attend the ceremony.
George HW Bush, who was in hospital for respiratory problems, wrote a letter to Trump wishing him well and apologising for missing the event due to health concerns.
An estimated 800,000 to 900,000 people are expected to flood the nation's capital on Friday for the inauguration, but it is unclear whether they will be there in celebration or protest, officials said.
President Barack Obama drew an estimated 1.8 million people to Washington when he took office eight years ago.
The "level of enthusiasm" and demand for hotel rooms has not reached that of previous inaugurations, according to Elliott Ferguson, president of Destination DC, the city's convention and tourism bureau.
In fact, some hotels have reduced the minimum-night stay from four nights to two.
Other hotels are only 50% full, but higher-end hotels appeared to have more bookings, he added.
Who is not going?
More than 50 House Democrats are publicly refusing to attend the ceremony amid a feud between the newly elected president and the civil rights activist and congressman, John Lewis.
Lewis is among the congressmen who will not be in attendance. Some lawmakers have said they will instead attend the Women's March on Washington, a protest set to take place a day after the inauguration.
(BBC)
