Why is "List of observances in the United States by presidential proclamation" trending?

Wikipedia Overview

U.S. law provides for the declaration of selected public observances by the President of the United States as designated by Congress or by the discretion of the President. Generally the President will provide a statement about the purpose and significance of the observance, and call on the people of the United States to observe the day "with appropriate ceremonies and activities". These events are typically to honor or commemorate a public issue or social cause, ethnic group, historic event or noted individual. However, there is no requirement that government or business close on these days, and many members of the general public may not be aware that such holidays even exist. Holidays proclaimed in this way may be considered a U.S. "national observance", but it would be improper to refer to them as "federal holidays". Many of these observances designated by Congress are authorized under permanent law under Title 36, U.S. Code, in which cases the President is under obligation to issue an annual proclamation.