The inauguration of the president of the United States is a ceremony to mark the commencement of a new four-year term of the president of the United States. As the new President-elect, Joe Biden is scheduled to be inaugurated on 20 Jan 2021.
After much speculation that she wouldn't, Hillary Clinton did attend Trump's inauguration, as is the tradition. Only three incumbent presidents have refused to attend the inauguration of the President-elect - John Adams, John Quincy Adams, and Andrew Johnson.
Will Donald Trump attend Joe Biden’s inauguration ceremony in person?
This question resolves "yes" if Trump attends a public event where Biden is sworn in as president, "no" if Trump does not attend.
This question resolves ambiguous if such an event does not occur by the end of 1 February 2021.
For positive resolution, Trump must be (a) within 800 meters of Joe Biden (b) for at least 80% of the entire inauguration ceremony and (c) is not hosting an alternative event or giving a speech for any amount of time that is contemporaneous with the inauguration ceremony.
The time period of "inauguration ceremony" refers to Biden's swearing in, plus the thirty minutes prior and thirty minutes after, or just the thirty minutes prior if there are not at least thirty minutes after, or just the thirty minutes after if there are not at least thirty minutes prior.