On January 20 (January 21 AEDT), Donald Trump was sworn in as the 45th President of the United States of America.

No more President-elect, no more PEOTUS. President Trump has officially taken office.

TL;DR: When is Trump president? Saturday, January 21, 4am AEDT (Noon EST) The term of the incoming president begins at noon on January 20 (local time)

The whole shindig is known as the Presidential Inauguration and it has a long history dating right back to the United States' first president, George Washington.

How can I watch it?

We've got you covered no matter where you're watching it. We'll have coverage across these channels:

When is everything happening?

Here's what time you can expect everything to happen on Inauguration Day. Some of the exact times have yet to be officially finalised, so treat these as a rough guide.

Saturday, 1:00am AEDT

The President-elect has attended a morning worship service.

Saturday, 1:30am AEDT

The Inaugural Swearing-in Ceremony has begun. The crowd was entertained by performers until the President-elect arrives.

Who's signed on to perform at Mr Trump's inauguration? Here's who you can expect to see (and who turned down an invite).

Saturday, 2:30am AEDT

President-elect Trump went to the White House for a meeting with soon-to-be former President Barack Obama. From there, they drove to the swearing-in ceremony at the US Capitol together.

Barack Obama and Donald Trump will meet in private one last time before the inauguration ceremony. ( AP: Pablo Martinez )

Saturday, 3:45am AEDT

Incoming vice-president Mike Pence has taken his oath of office.

Saturday, 4:00am AEDT

At noon (local time), the term of the new administration officially began. Mr Trump took the oath of office, administered by the Chief Justice of the United States, John Roberts.

It reads:

I do solemnly swear (or affirm) that I will faithfully execute the office of President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States.

We're now in the term of President Trump.

Saturday, 4:10am AEDT

President Trump delivered his Inaugural Address.

US President Barack Obama gives his inaugurational address after being sworn in. ( Reuters: Rob Carr/Pool )

Saturday, 5:00am AEDT

After the conclusion of the inaugural ceremony, Barack Obama and Vice-President Joe Biden (as well as their families) left the Capitol.

They were escorted out by the new President and Vice-President. Since the '70s, the former president and first lady have left the Capitol grounds by a helicopter, if weather permits.

Saturday, 5:30am AEDT

The new President took a break to grab something to eat.

The Inaugural Luncheon is organised by the Joint Congressional Committee on Inaugural Ceremonies and normally features food from the states of the new President and Vice-President (that's New York and Indiana for those playing along at home).

Saturday, 6:30am AEDT

After lunch, President Trump and Vice-President Pence lead the Inaugural Parade along Pennsylvania Avenue to the White House.

Members of the public will line the street, so expect plenty of well wishers and protesters as well.

The Inaugural Committee has announced there will be more than 8,000 participants marching in this year's parade.

Saturday, 11:00am AEDT

The day finishes with Inaugural Balls held across Washington.

Mr Trump has announced he'll attend two official balls on the night.