Columbus Day is traditionally the second Monday of October. It's a celebration of the founding of the Americas. The only places I know that celebrate this holiday are the federal government and Wall Street. My work, the school system, my church and the local government all ignore the holiday. I more or less get the sense that the feds made up this holiday, as an excuse to get a day off in October.
A lot of places are trying to replace Columbus Day with Indigenous People's Day, under the premise that Christopher Columbus was a horrible person who never set foot in the United States, and the colonization of our country was a complete human rights disaster involving slavery, genocide and other evils. Sarcastic people are saying White Guilt Day would be a more appropriate name.
I'm rather indifferent as to what the holiday is called, since I don't get to celebrate it either way. I'd say it's a nice gesture to name it after the natives.
The Columbus myth says that he was a heroic, bold explorer who wanted to prove the world was round. This was made up by Washington Irving in 1828. In reality, people officially knew the world was round, ever since the time of Aristotle (330 B.C.). I don't like this myth, because it usually puts the Catholic Church in the role of "illogical, science-hating villain who believes in a flat Earth". If getting rid of Columbus Day gets rid of this false myth, I'm all for it.