Barack Obama will hand over power to the incoming president at ceremonies in Washington DC today
After a divisive, hostile and often surreal US election last year, Donald Trump will be sworn in as the 45th President of the United States today.
Events got underway yesterday, with Mr Trump attending a wreath-laying ceremony in Virginia and a welcome concert at the Lincoln Memorial.
Today marks the official handover of power, with both the outgoing and incoming presidents taking part in proceedings.
We've broken it all down for you below, and make sure to tune into Newstalk Drive live in Washington from 4pm today.
13:45 - Mr and Mrs Trump attend prayer services at St John's Church.
15:00 - The Trumps meet the Obamas at the White House for tea.
15:45 - The two families will arrive at Capitol Hill.
16:15-16:30 - The inauguration ceremony begins.
Mike Pence will first take the Vice Presidential Oath, administered by Justice Clarence Thomas.
Shortly before 5pm Irish time (noon local time), Donald Trump takes Presidential oath, administered by Chief Justice John Roberts. The new president will then deliver his inaugural address.
17:15 - The US National Anthem will be sung by 16-year-old Jackie Evancho - a classical singer and former America's Got Talent contestant.
At the White House, meanwhile, there will be a flurry of activity as they have six hours to move the Obamas out and the Trumps in this afternoon.
17:45 - The new leaders will then go inside for a signing ceremony and an inaugural lunch of lobster and beef.
19:00 - Obamas board USAF 747 to depart Washington DC. They are due to holiday in Palm Springs.
19:45 - President Trump reviews troops on east front of Capitol, followed by the inaugural parade.
This evening, President Trump and the First Lady Melania Trump will also attend three inauguration balls.
Around a million people are expected to line the streets of the capital for the inauguration events. Elsewhere, there will be unofficial protests and celebrations throughout the day.
Meanwhile, organisers are hoping for at least 200,000 protesters at the Women's March in Washington DC tomorrow - likely to be the first of many major demonstrations over the coming weeks, months and years.
Donald Trump, meanwhile, will begin his first weekend in office:
It all begins today! I will see you at 11:00 A.M. for the swearing-in. THE MOVEMENT CONTINUES - THE WORK BEGINS!— Donald J. Trump (@realDonaldTrump) January 20, 2017
Additional reporting by IRN