Can't tell if it's because he's an illiterate dunce, or a narcissist. The singular form: "President's Day." Perhaps he thinks it's all about him?
Today in the United States, we celebrate Presidents' Day, a federal holiday to mark the birthday of America's first president, George Washington.
The President of the United States, however, is celebrating a different holiday.
In 2020, this day is all about Trump himself, just like every other day in this kleptocratic hellscape.
Here's the link to the original @realdonaldtrump tweet.